transmission fluid DODGE RAM 1999 Service User Guide
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switch sense circuit at O/D switch harness connector. If resistance is
less than 5 ohms, repair short to ground in O/D switch sense circuit.
If resistance is 5 ohms or greater, replace O/D off switch.
3) Conditions required to set DTC P0751 are not present at
this time. DTC P0751 sets if PCM senses O/D off switch input is held
low for 5 minutes or from time of closure or ignition on. Possible
causes are: faulty O/D OFF switch, shorted wire or faulty PCM. Inspect
all related wiring and connectors. Repair as necessary. If wiring and
connectors are okay, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC
SYSTEM. Testing is complete.
DTC P0753: TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS
Circuit Description
Circuit is monitored continuously while key is on. Code sets
if voltage detected on 3-4 shift solenoid control circuit at the
Powertrain Control Module (PCM) does not match expected voltage.
Possible Causes
* Transmission mechanically defective.
* TPS codes set.
* Transmission 3-4 solenoid wiring harness defective.
* Transmission fluid burnt or oil pan has excessive debris.
* Shift control solenoid circuit shorted to ground.
* Solenoid and harness assembly defective.
* Transmission control relay output circuit open.
* Transmission control relay output circuit shorted to
ground.
* PCM defective.
Diagnostic Procedure (AN & DN Bodies)
1) If DTC P1765 is also set, go to DTC P1765: TRANS 12-VOLT
SUPPLY RELAY CNTRL CIRCUIT. If DTC P1765 is not set, go to next step.
2) Road test vehicle and reach a speed of 50 MPH. Depress
Overdrive (OD) switch 4 times so vehicle attempts to shift from 4th
gear to 3rd gear and back. If vehicle does not shift between 3rd and
4th gear, go to step 5). If vehicle shifts between 3rd and 4th gear,
go to next step.
3) Using scan tool, erase DTCs. Start engine. Using scan
tool, read DTCs while wiggling wiring harness between 3-4 shift
solenoid and PCM. If DTC P0753 resets, repair wiring harness as
necessary. If DTC P0753 does not reset, go to next step.
4) Using wiring diagram as a guide, inspect wiring and
connectors. Repair wiring harness as necessary. If wiring and
connectors are okay, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC
SYSTEM. Testing is complete.
5) Turn ignition off. Disconnect transmission solenoid
harness connector. Turn ignition on. Using scan tool, actuate
transmission control relay. Measure voltage between ground and
transmission relay output circuit at transmission solenoid harness
connector. If voltage does not switch from zero to greater than 10
volts, go to step 16). If voltage switches from zero to greater than
10 volts, go to next step.
6) Turn ignition off. Disconnect PCM harness connectors.
Inspect connectors and terminals for damage. Repair as necessary. If
connectors and terminals are okay, turn ignition on. Measure voltage
between ground and 3-4 shift solenoid control circuit at transmission
solenoid harness connector. If voltage is greater than 10 volts, go to
next step. If voltage is 10 volts or less, go to step 8).
7) Repair 3-4 shift solenoid control circuit for short to
voltage. Reconnect all disconnected harness connectors. Road test
vehicle and reach a speed of 50 MPH. Depress Overdrive (OD) switch 4
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replace PCM and see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC
SYSTEM. Testing is complete.
DTC P0783: 3-4 SHIFT SOL, NO RPM DROP @ 3-4 SHIFT
Circuit Description
Circuit is monitored continuously while key is on and engine
running. Code sets if expected RPM drop does not occur within 4
seconds of requested gear change by PCM. Test must fail 3 times to set
code.
Possible Causes
* Transmission mechanically defective.
* TPS codes set.
* Transmission 3-4 solenoid wiring harness defective.
* Transmission fluid burnt or oil pan has excessive debris.
Diagnostic Procedures
1) Using scan tool, read DTCs. On all bodies except AB and WJ
bodies, go to next step. On AB and WJ bodies, if DTC SPECIFIC GOOD
TRIPS counter is not displayed or displayed count is not "0", go to
step 6). If DTC SPECIFIC GOOD TRIPS counter is displayed and displayed
count is "0", indicating DTC still exists, go to next step.
2) If any DTCs listed are present, perform appropriate
test(s). See 3-4 SHIFT SOLENOID TESTS table. If no DTCs are present,
go to next step.
3-4 SHIFT SOLENOID TESTS
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DTC Message Test
NO CAM SIGNAL AT PCM ..................................... ( 1) P0340
P/N SWITCH STUCK IN PARK OR IN GEAR .......................... P1899
Any Throttle Position Sensor (TPS) DTC ......................... ( 1)
TORQUE CONVERTOR CLUTCH SOLENOID/TRANS RELAY CIRCUITS ........ P0743
TRANS 12-VOLT SUPPLY RELAY CNTRL CIRCUIT ..................... P1765
TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS ................ P0753
( 1) - See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
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3) Check transmission fluid for proper level and for any
debris. Fill or repair transmission as necessary. If fluid level and
condition are okay, go to next step.
4) Connect a 0-300 psi (0-21 kg/cm
) pressure gauge to
transmission Overdrive (O/D) clutch pressure test port. Connect a
second 0-300 psi (0-21 kg/cm
) pressure gauge to transmission governor
pressure test port. See appropriate AUTOMATIC TRANSMISSION OVERHAUL
article. Ensure engine and transmission are at normal operating
temperature. With an assistant, test drive vehicle. Using scan tool,
select GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear while
monitoring pressure gauge. Governor pressure should rise to greater
than 20 psi (1.4 kg/cm
) and O/D pressure should rise to greater than
40 psi (2.8 kg/cm). If pressures are as specified, go to next step.
If pressures are not as specified, go to step 8).
5) Using wiring diagram as a guide, inspect wiring and
connectors. Repair wiring harness as necessary. If wiring and
connectors are okay, go to next step.
6) Using scan tool, erase DTCs. Start engine. Road test
vehicle at 0-55 MPH with a constant 20 percent throttle. Repeat road
test 4 times. Note if DTC P0783 resets. If DTC P0783 resets, repair
wiring harness as necessary. If DTC P0783 does not reset, go to next
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step.
7) Turn engine off. Drain transmission fluid and remove oil
pan. Inspect oil pan for burnt oil and debris. Repair transmission as
necessary. See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, no problem is found at this time, see INACTIVE
DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is complete.
8) Leave gauges connected. Replace 3-4 shift solenoid.
Replace transmission pan and fill with fluid. Start engine and allow
engine and transmission to reach normal operating temperature. Using
scan tool, select GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear
while monitoring pressure gauges. Governor pressure should rise to
greater than 20 psi (1.4 kg/cm
) and O/D pressure should rise to
greater than 40 psi (2.8 kg/cm). If pressures are as specified, no
problem is found at this time. Testing is complete. If pressures are
not as specified, see appropriate AUTOMATIC TRANSMISSION OVERHAUL
article, paying attention to seals and clutches related to O/D clutch.
DTC P1740: TCC OR O/D SOLENOID PERFORMANCE (BR BODY - DIESEL)
Circuit Description
Torque Converter Clutch (TCC) and overdrive clutch are tested\
when Powertrain Control Module (PCM) requests TCC engagement in 3rd
gear and overdrive. Code will set if expected RPM drop is not achieved
while attempting to engage TCC and/or overdrive. Code indicates
malfunctioning torque converter or overdrive clutch.
Possible Causes
* Fluid level or quality problem.
* Transmission wiring and connector defective.
* Transmission mechanically defective.
* Low fuel level.
* Trans temperature below 32
.
* Transfer case is in low range.
* Engine RPM trouble codes set.
* Misfire trouble code set (DTCs P0300-P0306).
* Output shaft speed trouble code set.
* PTO is engaged.
* TPS codes set (DTCs P0121-P0123).
* Torque converter defective.
Diagnostic Procedures
1) Using scan tool, read DTCs. If DTC SPECIFIC GOOD TRIPS
counter is not displayed or displayed count is not "0", go to step
16). If DTC SPECIFIC GOOD TRIPS counter is displayed and displayed
count is "0", go to next step.
2) If any DTCs listed are present, perform appropriate
test(s). See TCC OR O/D SOLENOID TESTS table. If no DTCs are present,
go to next step.
TCC OR O/D SOLENOID TESTS
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DTC Message Test
CAMSHAFT POSITION SENSOR SIGNAL .......................... ( 1) P0341
P/N SWITCH STUCK IN PARK OR IN GEAR .......................... P1899
Any Throttle Position Sensor (TPS) DTC ......................... ( 1)
Any Misfire DTC ................................................ ( 1)
Any Engine RPM DTC ............................................. ( 1)
Any Output Shaft Speed Sensor DTC .............................. ( 1)
TRANS 12-VOLT SUPPLY RELAY CNTRL CIRCUIT ..................... P1765
TORQUE CONVERTOR CLUTCH SOLENOID/TRANS RELAY CIRCUITS ........ P0743
TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS ................ P0753
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3) Ensure fuel tank is at least 1/4 full. If fuel level is
too low, correct fuel level and retest. If fuel level is okay, go to
next step.
4) Ensure transfer case is not in low range. Shift transfer
case out of low range. If transfer case is not in low range, go to
next step.
5) Ensure PTO is not engaged. Disengage PTO. If PTO is not
engaged, go to next step.
6) Ensure transmission fluid temperature is above 32
F (0C).
Warm transmission to normal operating temperature. If transmission
fluid temperature is above 32
F (0C), go to next step.
7) Turn ignition on. Using scan tool, build a custom display
with engine RPM, output shaft SPD, TCC solenoid, O/D solenoid and
throttle position. Set overdrive to off position. Road test vehicle
and reach a steady speed of 55 MPH with a minimum throttle opening
voltage of 1.15 volts for 20 seconds. Note shift patterns while
vehicle is attaining speed. If engine RPM is within 60 RPM of output
shaft speed RPM, go to next step. If engine RPM is not within 60 RPM
of output shaft speed RPM, go to step 15).
8) If output shaft speed RPM is greater than engine RPM, go
to next step. If output shaft speed RPM is equal to or less than
engine RPM, go to step 15).
9) Road test vehicle and reach a steady speed of 55 MPH and
engage overdrive. If engine RPM is 69 percent of output shaft speed,
go to step 15). If engine RPM is not 69 percent of output shaft speed,
go to next step.
10) Connect a 0-300 psi (0-21 kg/cm
) pressure gauge to
transmission Overdrive (O/D) clutch pressure test port. Connect a
second 0-300 psi (0-21 kg/cm
) pressure gauge to transmission governor
pressure test port. See appropriate AUTOMATIC TRANSMISSION OVERHAUL
article. Ensure engine and transmission are at normal operating
temperature. With an assistant, test drive vehicle. Using scan tool,
select GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear while
monitoring pressure gauge. Governor pressure should rise to greater
than 20 psi (1.4 kg/cm
) and O/D pressure should rise to greater than
40 psi (2.8 kg/cm). If pressures are as specified, go to next step.
If pressures are not as specified, go to step 13).
11) Check transmission fluid for proper level and for any
debris. Fill or repair transmission as necessary. If fluid level and
condition are okay, go to next step.
12) Drain transmission fluid and remove oil pan. If
transmission fluid is burnt or has excessive debris, repair as
necessary. If transmission fluid is okay, go to step 23).
13) Check transmission fluid for proper level and for any
debris. Fill or repair transmission as necessary. If fluid level and
condition are okay, go to next step.
14) Leave gauges connected. Replace 3-4 shift solenoid. Start
engine and allow engine and transmission to reach normal operating
temperature. Using scan tool, select GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear while monitoring pressure gauges. Governor
pressure should rise to greater than 20 psi (1.4 kg/cm
) and O/D
pressure should rise to greater than 40 psi (2.8 kg/cm). If pressures
are as specified, testing is complete. If pressures are not as
specified, see appropriate AUTOMATIC TRANSMISSION OVERHAUL article,
paying attention to seals and clutches related to O/D clutch.
15) Check transmission fluid for proper level and for any
debris. Fill or repair transmission as necessary. If fluid level and
condition are okay, go to next step.
16) Start engine. Using scan tool, perform TCC SYSTEM TEST.
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If engine stalls, go to next step. If engine does not stall, go to
step 19).
17) Using scan tool, select GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear. If engine stalls, go to next step. If engine
does not stall, go to step 23).
18) Replace TCC solenoid. Perform GOV and 3-4 SHIFT VALVE
SYSTEM TEST. Select 4th gear. If engine stalls, repair internal
problem. Check for internally blocked passages. See appropriate
AUTOMATIC TRANSMISSION OVERHAUL article. If engine does not stall,
test is complete.
19) Turn ignition off. Remove oil pump. Inspect reaction
shaft, input shaft and input seal. If any parts are damaged, repair as
necessary and go to next step. If all parts are okay, replace torque
converter.
20) Start engine. Perform GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear. If engine stalls, go to next step. If engine
does not stall, go to step 23).
21) Turn ignition off. Replace TCC solenoid. Start engine.
Perform GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear. If
engine stalls, repair internal problem. Check for internally blocked
passages. See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
engine does not stall, go to next step.
22) Turn ignition off. Remove oil pump. Inspect reaction
shaft, input shaft and input seal. If any parts are damaged, repair as
necessary and replace torque converter. If all parts are okay, test is
complete.
23) Turn ignition off. Remove oil pump. Inspect reaction
shaft, input shaft and input seal. If any parts are damaged, repair as
necessary and replace torque converter. If all parts are okay, go to
next step.
24) Record freeze frame data to determine conditions when
code was set. Using wiring diagram as a guide, inspect wiring and
connectors. Repair wiring harness as necessary. If wiring and
connectors are okay, go to next step.
25) Using scan tool, erase DTCs. Start engine. Attempt to
duplicate data and reset code. Road test vehicle maintaining a
constant throttle opening voltage of 1.15 volts, reach a speed of 60
MPH. Repeat road test 4 times. Note if DTC P1740 resets. If DTC P1740
resets, there are no other possible causes remaining. Problem is
considered to be an intermittent problem in wiring harness connector
or wire. See INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM.
Repair wiring harness as necessary. If DTC P1740 does not reset,
testing is complete.
DTC P1756: GOV PRESS NOT EQUAL TO TARGET @ 15-20 PSI
Circuit Description
Circuit is monitored continuously while key is on and engine
running, not in Park or Neutral position or with Malfunction Indicator
Light (MIL) illuminated. Code sets if governor pressure sensor output
is not 15-30 psi (1.0-2.1 kg/cm
) when requested pressure is 20-25 psi
(1.4-1.7 kg/cm) for 2.2 seconds. Test must fail 5 times to set code.
Possible Causes
* Other transmission codes are set.
* Solenoid pack connector 5 volt supply circuit open.
* Governor pressure sensor defective.
* Transmission fluid burnt or oil pan has excessive debris.
* Governor pressure out of range.
* Transmission leaking internally.
Diagnostic Procedures
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1) Using scan tool, read DTCs. On AN and DN bodies, go to
next step. On all except AN and DN bodies, if DTC SPECIFIC GOOD TRIPS
counter is not displayed or displayed count is not "0", go to step
15). If DTC SPECIFIC GOOD TRIPS counter is displayed and displayed
count is "0", go to next step.
2) Repair any other transmission related DTCs before
proceeding. See DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES table.
If no other transmission related DTCs exist, go to next step.
3) Start engine. Allow engine to reach normal operating
temperature. Set parking brake, depress brake pedal and place gear
selector in "D" position. Using scan tool, read governor pressure
sensor value. If value is greater than 3 psi (.2 kg/cm
), go to next
step. If value is 3 psi (.2 kg/cm) or less, go to step 7).
4) Turn ignition off. Install a pressure gauge at
transmission governor pressure test port. See TESTING in appropriate
AUTOMATIC TRANSMISSION OVERHAUL article. Start engine. With gear
selector in "D” position, read gauge pressure. If pressure is
less than 5 psi (.3 kg/cm
), go to step 12). If pressure is 5 psi (.3
kg/cm) or greater, go to next step.
5) Turn engine off. Drain transmission fluid and remove oil
pan. Inspect oil pan for burnt oil and debris. Repair transmission as
necessary. See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, go to next step.
6) Replace governor pressure solenoid. Start engine. Read
gauge pressure. If pressure is less than 5 psi (.3 kg/cm
), testing is
complete. If pressure is 5 psi (.3 kg/cm) or greater, replace valve
body.
NOTE: Removing transmission control relay in the following step may
set other DTCs. Disregard these DTCs.
7) Place gear selector in Park. With engine still running,
remove transmission control relay. Depress brake pedal and place gear
selector in "D" position. Read governor pressure sensor value. If
value is 40-55 psi (2.8-3.9 kg/cm
), go to next step. If value is not
as specified, go to step 10).
8) Turn engine off. Install transmission control relay. Drive
vehicle at 25-30 MPH. Using scan tool, monitor governor actual
pressure and target pressure. If pressures do not stay consistently
within 5 psi (.3 kg/cm
) of each other within 3 seconds, go to next
step. If pressures stay consistently within 5 psi (.3 kg/cm) of each
other, test is complete.
9) Replace governor pressure solenoid. Drive vehicle at 25-30
MPH. Using scan tool, monitor governor actual pressure and target
pressure. If pressures do not stay consistently within 5 psi (.3
kg/cm
) of each other, repair internal transmission leakage problem.
If pressures stay consistently within 5 psi (.3 kg/cm) of each other,
testing is complete.
10) On all bodies except WJ body, go to next step. On WJ
body, turn ignition on, engine off. Measure voltage (backprobe)
between ground and 5-volt supply circuit at transmission solenoid
harness connector. If voltage is 4.5 volts or less, repair 5-volt
supply circuit for low voltage. If voltage is greater than 4.5 volts,
go to next step.
11) Turn ignition off. Install transmission control relay.
Install a pressure gauge at governor pressure test port. See TESTING
in appropriate AUTOMATIC TRANSMISSION OVERHAUL article. Start engine.
Remove transmission control relay. Depress brake pedal and place gear
selector in "D" position. Read gauge pressure. If pressure is 40-55
psi (2.8-3.9 kg/cm
), go to next step. If pressure is not as
specified, go to step 13).
12) Turn ignition off. Disconnect transmission solenoid
harness connector. Inspect connector and terminals for damage. Repair
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as necessary. If connector and terminals are okay, turn ignition on.
Measure voltage between ground and 5-volt supply circuit at
transmission solenoid harness connector. If voltage is 4.5 volts or
less, repair open 5-volt supply circuit. If voltage is greater than 4.
5 volts, replace governor pressure sensor.
13) Turn engine off. Install transmission control relay.
Drain transmission fluid and remove oil pan. Inspect pan for burnt oil
and debris. Repair transmission as necessary. See appropriate
AUTOMATIC TRANSMISSION OVERHAUL article. If transmission is okay, go
to next step.
14) Replace governor pressure solenoid. Replace transmission
oil pan and refill fluid. Start engine. Remove transmission control
relay. Depress brake pedal and place gear selector in "D" position.
Read gauge pressure. If pressure is 40-55 psi (2.8-3.9 kg/cm
),
testing is complete. If pressure is not as specified, replace valve
body.
15) Conditions required to set DTC P1756 are not present at
this time. Using scan tool, clear DTCs. Start engine and check for
DTCs. Wiggle wiring harness between governor pressure sensor and PCM.
Note if DTC P1756 resets. If DTC P1756 resets, repair wiring harness
as necessary. If DTC P1756 does not reset, see INACTIVE DTC CONDITION
under SELF-DIAGNOSTIC SYSTEM. Testing is complete.
DTC P1757: GOV PRES ABOVE 3 PSI IN GEAR WITH 0 MPH
Circuit Description
Circuit is monitored continuously while key is on and engine
running, not in Park or Neutral position or with Malfunction Indicator
Light (MIL) illuminated. Code sets if governor pressure sensor is
greater than 3 psi (.2 kg/cm
) when requested pressure is zero with
governor pressure solenoid duty cycle at 95 percent for 2.65 seconds.
Test must fail twice to set code.
Possible Causes
* Other transmission codes are set.
* Solenoid pack connector 5-volt supply circuit open.
* Governor pressure sensor defective.
* Wiring harness and/or connectors defective.
* Transmission fluid burnt or oil pan has excessive debris.
* Valve body defective.
Diagnostic Procedures
1) Using scan tool, read DTCs. On AN and DN bodies, go to
next step. On all except AN and DN bodies, if DTC SPECIFIC GOOD TRIPS
counter is not displayed or displayed count is not "0", go to step 8).
If DTC SPECIFIC GOOD TRIPS counter is displayed and displayed count is
"0", go to next step.
2) Repair any other transmission related DTCs before
proceeding. If no other transmission related DTCs exist, go to next
step.
3) Start engine. Allow engine to reach normal operating
temperature. Set parking brake, depress brake pedal and place gear
selector in "D" position. Using scan tool, read governor pressure
sensor value. If value is greater than 3 psi (.2 kg/cm
), go to next
step. If value is 3 psi (.2 kg/cm) or less, go to step 8).
4) Turn ignition off. Install a pressure gauge at governor
pressure test port. See TESTING in appropriate AUTOMATIC TRANSMISSION
OVERHAUL article. Start engine. With gear selector in "D" position,
read gauge pressure. If pressure is less than 3 psi (.2 kg/cm
), go to
step 7). If pressure is 3 psi (.2 kg/cm) or greater, go to next step.
5) Turn engine off. Drain transmission fluid and remove oil
pan. Inspect oil pan for burnt oil and debris. Repair transmission as
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necessary. See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, go to next step.
6) Replace governor pressure solenoid. Replace transmission
oil pan and refill fluid. Start engine. Read gauge pressure. If
pressure is less than 3 psi (.2 kg/cm
), testing is complete. If
pressure is 3 psi (.2 kg/cm) or greater, replace valve body.
7) Turn ignition off. Disconnect transmission solenoid
harness connector. Inspect connector and terminals for damage. Repair
as necessary. If connector and terminals are okay, turn ignition on.
Measure voltage between ground and 5-volt supply circuit at
transmission solenoid harness connector. If voltage is 4.5 volts or
less, repair open 5-volt supply circuit. If voltage is greater than 4.
5 volts, replace governor pressure sensor.
8) Using scan tool, read and record FREEZE FRAME data. Ensure
CAUSED BY DTC hex code matches DTC message on screen. Using wiring
diagram as a guide, inspect wiring and connectors. Repair wiring
harness as necessary. If wiring and connectors are okay, go to next
step.
9) Using scan tool, clear DTCs. Drive vehicle at 0-20 MPH and
come to complete for 20 seconds. Repeat road test 5 times. Using scan
tool, monitor governor actual pressure and target pressure. If
pressures greater than 3 psi (.2 kg/cm
) at zero MPH appears, repair
wiring harness as necessary. If pressures greater than 3 psi (.2
kg/cm
) at zero MPH do not appear, testing is complete.
DTC P1762: GOV PRESS SEN OFFSET VOLTS TOO LOW OR HIGH
Circuit Description
Circuit is monitored continuously while key is on and engine
running. Code sets if governor pressure is out of range for 1.3
seconds. Test must fail 3 times to set code.
Possible Causes
* Solenoid pack connector 5 volt supply circuit open.
* Governor pressure sensor ground circuit open.
* Governor pressure sensor wiring harness and/or connectors
defective.
* Transmission fluid burnt or oil pan has excessive debris.
Diagnostic Procedures
1) Using scan tool, read DTCs. On AN and DN bodies, go to
next step. On all except AN and DN bodies, if DTC SPECIFIC GOOD TRIPS
counter is not displayed or displayed count is not "0", go to step 9).
If DTC SPECIFIC GOOD TRIPS counter is displayed and displayed count is
"0", go to next step.
2) Start engine and allow it to reach normal temperature.
Check transmission fluid level and condition. Correct transmission
fluid level or condition as necessary. If transmission fluid level and
condition are okay, go to next step.
3) Turn ignition off and back on. Do not start. Using scan
tool, check Park/Neutral Position (PNP) switch operation. Repair PNP
switch as necessary. If PNP switch operation is okay, go to next step.
4) Start engine. Place gear selector in Neutral. Using scan
tool, read GOV PRESSURE voltage. If voltage is not .30-.76 volt, go to
step 6). If voltage is as specified, go to next step.
5) While monitoring GOV PRESSURE sensor voltage, wiggle
connectors and wiring harness between governor pressure sensor and
PCM. If voltage changes while wiggling connectors and harness, repair
connector or harness as necessary. If voltage does not change,
conditions required to set DTC P1762 are not present at this time. DTC
P1762 sets if governor pressure sensor input is less than or greater
than a predetermined PNP switch calibration for 1.3 seconds under
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predetermined conditions. Possible causes are: faulty governor
pressure sensor, shorted or open 5-volt supply circuit or faulty PCM.
Testing is complete.
6) While monitoring GOV PRESSURE sensor voltage, wiggle
connectors and wiring harness between governor pressure sensor and
PCM. If voltage changes while wiggling connectors and harness, repair
connector or harness as necessary. If voltage does not change, go to
next step.
7) Read and record FREEZE FRAME data. Turn ignition off.
Disconnect transmission solenoid harness connector. Inspect connector
and terminals for damage. Repair as necessary. If connector and
terminals are okay, turn ignition on. Measure voltage between ground
and 5-volt supply circuit at transmission solenoid harness connector.
If voltage is less than 4.5 volts, repair open 5-volt supply circuit.
If voltage is 4.5 volts or greater, go to next step.
8) Turn ignition off. Disconnect PCM harness connectors.
Inspect connectors and terminals for damage. Repair as necessary. If
connectors and terminals are okay, measure resistance of ground
circuit between transmission solenoid harness connector and Black PCM
harness connector C1. If resistance is 5 ohms or greater, repair open
ground circuit. If resistance is less than 5 ohms, go to next step.
9) Reconnect all harness connectors. Start engine. Use scan
tool to read and record FREEZE FRAME data. Erase DTCs. Start engine
and allow it to idle in Neutral or Park for 3 minutes. Read DTCs. If
DTC P1762 does not reset test is complete. If DTC P1762 resets, go to
next step.
10) Drain transmission fluid and remove oil pan. Replace
governor pressure sensor. Inspect oil pan for burnt oil and debris.
Repair transmission as necessary. See appropriate AUTOMATIC
TRANSMISSION OVERHAUL article. If transmission is okay, no problem is
found at this time. Testing is complete.
DTC P1763: GOVERNOR PRESSURE SENSOR VOLTS TOO HIGH
Circuit Description
Circuit is monitored continuously while key is on and engine
running. Code sets if governor pressure signal voltage is greater than
4.89 volts for 8.5 seconds.
Possible Causes
* Solenoid pack connector 5 volt supply circuit open.
* Governor pressure sensor ground circuit open.
* Governor pressure sensor wiring harness and/or connectors
defective.
* Governor pressure/temperature sensor defective.
* Governor pressure sensor signal circuit short to voltage.
* Governor pressure sensor signal circuit open.
* PCM defective.
Diagnostic Procedures
1) Using scan tool read DTCs. If DTC SPECIFIC GOOD TRIPS
counter is not displayed or displayed count is not "0", go to step
22). If DTC SPECIFIC GOOD TRIPS counter is displayed and displayed
count is "0", indicating DTC still exists, go to next step.
2) Turn ignition off. Disconnect transmission solenoid
harness connector. Inspect connector and terminals for damage. Repair
as necessary. If connector and terminals are okay, turn ignition on.
Measure voltage between ground and 5-volt supply circuit at
transmission solenoid harness connector. If voltage is 4.5-5.5 volts,
go to next step. If voltage is not as specified, repair open 5-volt
supply circuit.
3) Reconnect transmission solenoid harness connector. Using
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scan tool, read governor pressure sensor voltage. If voltage is
greater than 4.65 volts, go to next step. If voltage is 4.65 volts or
less, go to step 11).
4) Turn ignition off. Disconnect transmission solenoid
harness connector. Disconnect PCM harness connectors. Inspect
connectors and terminals for damage. Repair as necessary. If connector
and terminals are okay, measure resistance of governor pressure sensor
signal circuit between transmission solenoid harness connector and
White PCM harness connector C2. If resistance is greater than 5 ohms,
repair open governor pressure sensor signal circuit. If resistance is
5 ohms or less, go to next step.
5) Measure resistance of sensor ground circuit between Black
PCM harness connector C1 and transmission solenoid harness connector.
If resistance is greater than 5 ohms, repair open ground circuit. If
resistance is 5 ohms or less, go to next step.
6) Connect a fused jumper wire between fused B+ circuit and
transmission control relay output circuit at transmission relay
connector. Turn ignition on. Measure voltage between ground and
governor pressure signal circuit at White PCM harness connector C2. If
voltage is greater than 10 volts, repair governor pressure signal
circuit for short to voltage. If voltage is 10 volts or less, go to
next step.
7) Turn ignition off. Drain transmission fluid and remove oil
pan. Reconnect transmission solenoid harness connector. Disconnect
governor pressure sensor harness connector. Inspect connector and
terminals for damage. Repair as necessary. If connector and terminals
are okay, measure resistance of governor pressure sensor ground
circuit between Black PCM harness connector C1 and governor pressure
sensor harness connector. If resistance is greater than 5 ohms, repair
or replace transmission solenoid and harness assembly. If resistance
is 5 ohms or less, go to next step.
8) Reconnect all harness connectors except governor pressure
sensor harness connector. Carefully connect a fused jumper wire
between ground circuit and governor pressure signal circuit at
governor pressure sensor harness connector. Turn ignition on. Using
scan tool, read governor pressure sensor voltage. If voltage is .1
volt or less, replace governor pressure sensor. If resistance is
greater than .1 volt, go to next step.
9) Measure resistance of governor pressure sensor signal
circuit between White PCM harness connector C2 and governor pressure
sensor harness connector. If resistance is greater than 5 ohms, repair
or replace transmission solenoid and harness assembly. If resistance
is 5 ohms or less, go to next step.
10) Turn ignition on. Measure voltage between ground and
governor pressure signal circuit at governor pressure sensor harness
connector. If voltage is greater than one volt, repair or replace
transmission solenoid and harness assembly. If voltage is one volt or
less, replace PCM.
11) If governor pressure voltage is less than .12 volt, go to
DTC P1764: GOVERNOR PRESSURE SENSOR VOLTS TOO LOW. If governor
pressure voltage is .12 volt or greater, go to next step.
12) If governor pressure voltage is .12-.80 volt, go to next
step. If governor pressure voltage is .80 volt or greater, go to step
15).
13) Wiggle wiring harness between PCM and governor pressure
sensor while monitoring governor pressure voltage on scan tool. If
voltage changes while wiggling wiring harness, repair wiring harness
as necessary. If voltage does not change, go next step.
14) Conditions required to set DTC P1763 are not present at
this time. DTC P1763 sets if governor pressure sensor input is greater
than 4.89 volts for 8.36 seconds. Possible causes are: PCM internally
shorted or open, incorrectly wired, dirty or corroded connectors or
open or shorted wiring. See INACTIVE DTC CONDITION under SELF-