engine DODGE RAM 1999 Service Manual PDF
[x] Cancel search | Manufacturer: DODGE, Model Year: 1999, Model line: RAM, Model: DODGE RAM 1999Pages: 1691, PDF Size: 40.34 MB
Page 208 of 1691
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Ensure ignition switch is in the RUN position. Disconnect
Powertrain Control Module (PCM) connectors. If DRB does not display
BUS SHORT TO BATTERY, to step 8). If DRB displays BUS SHORT TO
BATTERY, go to next step.
2) Disconnect instrument cluster connectors. If DRB does not
display BUS SHORT TO BATTERY, replace instrument cluster. If DRB
displays BUS SHORT TO BATTERY, go to next step.
3) Turn ignition off and wait 2 minutes before proceeding.
Disconnect air bag control module connector. Turn ignition on (engine
off). If DRB does not display SHORT TO BATTERY, replace ACM. If DRB
displays SHORT TO BATTERY, go to next step.
4) Disconnect Central Timer Module (CTM) 18-pin connector. I\
f
DRB does not display BUS SHORT TO BATTERY, replace CTM. If DRB
displays BUS SHORT TO BATTERY, go to next step.
5) Disconnect anti-lock brake controller. If DRB does not
display BUS SHORT TO BATTERY, replace anti-lock brake controller. If
DRB displays BUS SHORT TO BATTERY, go to next step.
6) Disconnect DRB from Data Link Connector (DLC). Using a
voltmeter, check voltage between ground and DLC connector terminal No.
3 (Violet/Brown wire). If voltage is more than 0.2 volt, repair short
in Violet/Brown wire. If voltage is less than 0.2 volt, go to next
step.
7) Using a voltmeter, check voltage between ground and DLC
connector terminal No. 11 (White/Black wire). If voltage is more than
0.2 volt, repair short in White/Black wire. If voltage is less than 0.
2 volt, replace DRB or DRB cable as necessary.
8) Turn ignition off. Using an ohmmeter, check resistance
between ground and PCM Black connector terminal A31 (Black/Tan wire).
If resistance is more than 10 ohms, repair open in Black/Tan wire). If
resistance is less than 10 ohms, go to next step.
9) Using an ohmmeter, check resistance between ground and PCM
Black connector terminal A32 (Black/Tan wire). If resistance is more
than 10 ohms, repair open in Black/Tan wire). If resistance is less
than 10 ohms, replace Powertrain Control Module (PCM).
NO RESPONSE FROM INSTRUMENT CLUSTER
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Remove Instrument cluster. Using DRB, turn on INTERNAL BUS
BIAS under SYSTEM MONITORS CCD BUS VOLTAGE. Connect a jumper wire from
Black instrument cluster 10-pin connector "A" terminal No. 9
(White/Black wire) to ground. Observe CCD BUS voltage on DRB. If
voltage did not drop to about zero volt, repair open in White/Black
wire. If voltage drops to about zero volt, go to next step.
2) Leave internal DRB CCD BUS BIAS turned on. Connect a
jumper wire from ground to Black instrument cluster 10-pin connector
"A" terminal No. 10 (Violet/Brown wire). Go to next step.
3) Observe CCD BUS voltage on DRB. If voltage did not drop to
about zero volt, repair open in Violet/Brown wire. If voltage drops to
about zero volt, replace instrument cluster.
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AN TI- T H EFT S YSTE M
1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Anti-Theft Systems
Ram Pickup, Ram Van & Ram Wagon
DESCRIPTION
The Vehicle Theft Security System (VTSS) provides an engine
no-run feature, flashes headlights and sounds horn if any door or hood
is opened without using key or remote keyless entry transmitter, or if
battery cables are disconnected then reconnected when system is
activated.
Anti-theft system is controlled by Central Timer Module
(CTM). CTM is located under driver's side of dash panel, right of
steering column. If CTM is faulty, CTM cannot be repaired and must be
replaced.
VTSS is also equipped with a power-up mode. If battery is
disconnected or looses power while VTSS is armed, VTSS system remains
armed when power is restored. A temper alert signal is sounded on
vehicle entry if VTSS was triggered while away from vehicle. Horn will
sound 3 times alerting owner VTSS was triggered.
OPERATION
ARMING PROCEDURE (PASSIVE)
Remove key from ignition. Ensure headlights are off. Lock
doors while open, using power lock switch. Power lock switch will not
operate with key in ignition or headlights on while door is open.
Vehicle Theft Security System (VTSS) will not arm using key in lock
cylinder or mechanical lock button. While system is arming, SECURITY
light will flash rapidly for 15 seconds. Opening any door or turning
the ignition key while light is flashing will abort arming process.
Once arming process is complete, SECURITY light will go out.
ARMING PROCEDURE (ACTIVE)
Pressing Remote Keyless Entry (RKE) transmitter LOCK button
will actively arm Vehicle Theft Security System (VTSS). All doors must\
be closed and ignition switch in OFF position. While system is arming,
SECURITY light will flash rapidly for 15 seconds. Opening any door or
turning the ignition key while light is flashing will abort arming
process. Once arming process is complete, SECURITY light will go out.
DISARMING
Vehicle Theft Security System (VTSS) can be disarmed 2 ways:
unlock vehicle using key in any door and pressing remote keyless entry
transmitter UNLOCK button. If alarm has been set off, either method
can be used to disarm and shut-off horn.
CENTRAL TIMER MODULE (CTM)
Central Timer Module (CTM) is Vehicle Theft Security System
(VTSS) processor. CTM uses the data bus network to allow sharing and
reporting of sensor information. If a door ajar sensor is opened while
VTSS is set, a signal is sent to flash headlights and sound horn. PCM
is also notified through bus network to enable engine no-run feature.
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CTM has remote keyless entry receiver and control logic incorporated.
COMPONENT TESTS
RELAYS
NOTE: Headlight relay may also be referred to as the security
relay. On Ram Pickup, the headlight relay is located in Power
Distribution Center (PDC) in engine compartment. On Ram Van
and Ram Wagon, the headlight relay is taped to headlight
switch harness. On Ram Pickup, the horn relay is located in
Power Distribution Center (PDC) in engine compartment. On Ram\
Van and Ram Wagon, the horn relay is located in junction
block under left side of instrument panel. For circuit
testing, see WIRING DIAGRAMS.
Headlight Relay & Horn Relay
Remove relay to be tested. Measure resistance between
appropriate relay terminals with relay de-energized and energized. See
RELAY TEST SPECIFICATIONS table. See Fig. 1. If continuity or
resistance is not as specified, replace relay.
RELAY TEST SPECIFICATIONS
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Terminals Condition
De-Energized
87A & 30 .............................................. Continuity
87 & 30 ............................................ No Continuity
85 & 86 .................................... 70-80 Ohms Resistance
Energized ( 1)
87 & 30 ............................................... Continuity
87A & 30 ........................................... No Continuity
( 1) - Apply position battery voltage to terminal No. 85 and ground
terminal No. 86.
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Fig. 1: Identifying Relay Connector Terminals
Courtesy of Chrysler Corp.
SYSTEM TESTS
Page 222 of 1691
stretched, cut or pinched wiring. Ensure electrical connectors fit
tightly and are not corroded. Check PCM, sensors and switches for
physical damage. Check engine coolant level. Check transmission fluid
level and condition.
SELF-DIAGNOSTIC SYSTEM
* PLEASE READ THIS FIRST *
NOTE: Only transaxle-related trouble codes are listed. For engine-
related DTC definitions, see TROUBLE CODE DEFINITIONS article
in APPLICATIONS & IDENTIFICATION. For engine-related DTC
diagnosis, see appropriate SELF-DIAGNOSTICS article in ENGINE
PERFORMANCE. Engine performance DTCs must be repaired first,
as engine performance and related component signals will
affect transaxle operation and diagnosis.
DIAGNOSTIC PROCEDURE
When performing vehicle diagnosis:
* Ensure transmission fluid level is correct and fluid is
neither contaminated or aerated.
* Ensure shift cable is properly adjusted. See appropriate
AUTOMATIC TRANSMISSION SERVICING article in TRANSMISSION
SERVICING.
* Ensure battery is fully charged.
* Perform visual inspection, ensuring all electrical
connections at transmission, PCM, TP sensor and output shaft
speed sensor are clean and properly installed.
* Retrieve DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES.
* Repair DTCs in order displayed.
* Always perform test verification test after any repair
procedure is completed unless specified otherwise. See
appropriate verification test under DIAGNOSTIC TESTS.
NOTE: Self-diagnostic tests are written specifically for Chrysler's
Diagnostic Readout Box (DRB) scan tool. A generic scan tool
may be used, but may not be capable of performing all
necessary test functions.
TEST EQUIPMENT HOOK-UP
Generic Scan Tool & DVOM
Self-diagnostic tests are written specifically for Chrysler's
Diagnostic Readout Box (DRB) scan tool. The DRB has a built-in DVOM
function. A generic scan tool may be used, but may not be capable of
performing all necessary test functions. If DRB test procedures
require resistance or voltage to be measured using scan tool in
ohmmeter or voltmeter mode, connect DVOM ground lead to DLC connector
terminal No. 4 and positive lead to terminal specified in test
procedure.
DRB Scan Tool
Refer to DRB scan tool instructions to read and clear DTCs,
and when performing other scan tool functions. DRB scan tool is
grounded through DLC connector terminal No. 4. Only one volt/ohmmeter
test lead is required to measure voltage or resistance. See Fig. 2.
RETRIEVING DIAGNOSTIC TROUBLE CODES
NOTE: Manufacturer recommends using Chrysler's Diagnostic Readout
Page 231 of 1691
* PLEASE READ THIS FIRST *
NOTE: For engine-related DTCs, see appropriate SELF-DIAGNOSTICS
article in ENGINE PERFORMANCE. Engine performance DTCs must
be repaired first, as engine performance and related
component signals will affect transmission operation and
diagnosis.
All references to Using scan tool, perform TCC SYSTEM TEST
are for scan tool driven testing of TCC system. Follow manufactures
scan tool instructions.
All connector references in the following testing apply to
harness connectors unless otherwise specified. For circuit, wire color
and connector terminal identification, see CONNECTOR IDENTIFICATION
and WIRING DIAGRAMS. After all repairs are complete or any component
is replaced, perform verification test as follows:
* DTC P0751 perform appropriate verification VER-2A.
* All DTCs except P0751 perform appropriate verification
VER-5A.
DTC P0711: TRANS TEMP SENSOR, NO TEMP RISE AFTER START
NOTE: To test transmission temperature sensor, engine and
transmission temperature must be less than 85F (29C).
1) Using scan tool, read DTCs. If DTCs P0712, P0713 or P1899
are present, repair these DTCs before proceeding. If neither of these
DTCs are present, go to next step.
2) Using scan tool, read and record Engine Coolant
Temperature (ECT) sensor temperature, and transmission temperature
sensor temperature. If transmission temperature is within 9
F (-13C)
of ECT temperature, go to step 5). If transmission temperature is not
within 9
F (-13C) of ECT temperature, go to next step.
3) Start engine and let it idle in gear, with brake on.
Monitor transmission temperature sensor. If transmission temperature
does not increase steadily 15
F (-9C) over a 10 minute period, go to
step 5). If transmission temperature increases steadily 15F (-9C)
over a 10 minute period, go to next step.
4) 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.
5) Disconnect transmission solenoid harness connector.
Inspect connector and terminals for damage. Repair as necessary. If
connector and terminals are okay, replace transmission governor
pressure/temperature sensor.
DTC P0712: TRANS TEMP SENSOR VOLTAGE TOO LOW
Circuit Description
Circuit is monitored continuously while key is on, and engine
running. Code sets if transmission temperature sensor voltage is less
than 1.55 volts for 2.2 seconds.
Possible Causes
* Transmission temperature sensor wiring harness defective.
* Transmission pressure/temperature sensor defective.
* Transmission temperature signal circuit short to ground.
* Transmission temperature signal circuit short to sensor
ground circuit.
* PCM defective.
Page 232 of 1691
Diagnostic Procedures
1) On AN and DN bodies, go to next step. On all except AN and
DN bodies, record freeze frame data. Use scan tool to read DTCs. If
DTC SPECIFIC GOOD TRIPS counter is not displayed or displayed count is
not "0", go to step 11). If DTC SPECIFIC GOOD TRIPS counter is
displayed and displayed count is "0", go to next step.
2) Turn ignition off. Disconnect PCM harness connectors.
Inspect connectors and terminals for damage. Repair as necessary. If
connectors and terminals are okay, measure resistance between
transmission temperature signal circuit at White PCM harness connector
C2 and ground circuit at Black PCM harness connector C1. If resistance
is less than 550 ohms, go to step 8). If resistance is 550 ohms or
more, go to next step.
3) If resistance is 550-2300 ohms, go to next step. If
resistance is greater than 2300 ohms, go to DTC P0713: TRANS TEMP
SENSOR VOLTAGE TOO HIGH.
4) Measure resistance of transmission temperature signal
circuit between ground and White PCM harness connector C2. If
resistance is 5 ohms or less, go to step 8). If resistance is greater
than 5 ohms, go to next step.
5) Reconnect all harness connectors. Using scan tool, read
TRANS TEMP voltage. If voltage is less than 1.5 volts, replace PCM. If
voltage is 1.5 volts or greater, go to step 7). On all other bodies,
go to next step.
6) Conditions required to set DTC P0712 are not present at
this time. DTC P0712 sets when transmission temperature sensor voltage
at PCM is less than 1.55 volts for 2.2 seconds. Possible causes are:
shorted transmission temperature sensor wiring, faulty connections,
faulty transmission temperature sensor or faulty PCM. Go to next step.
7) 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.
8) Disconnect transmission solenoid harness connector.
Inspect connector and terminals for damage. Repair as necessary. If
connector and terminals are okay, measure resistance between
transmission temperature signal circuit at White PCM harness connector
C2 and sensor ground circuit at Black PCM harness connector C1. If
resistance is less than 5 ohms, repair transmission temperature signal
circuit for short to ground circuit. If resistance is 5 ohms or
greater, go to next step.
9) Measure resistance between ground and transmission
temperature signal circuit at White PCM harness connector C2. If
resistance is less than 5 ohms, repair transmission temperature signal
circuit for short to ground. If resistance is 5 ohms or greater, go to
next step.
10) Reconnect transmission solenoid harness connector. Remove
transmission oil pan. Disconnect transmission pressure/temperature
sensor harness connector. Measure resistance between transmission
temperature signal circuit at White PCM harness connector C2 and
sensor ground circuit at Black PCM harness connector C1. If resistance
is less than 5 ohms, repair or replace transmission solenoid and
harness assembly. If resistance is 5 ohms or greater, go to next step.
11) Measure resistance between ground and transmission
temperature signal circuit at White PCM harness connector C2. If
resistance is less than 5 ohms, repair or replace transmission
solenoid and harness assembly. If resistance is 5 ohms or greater,
replace transmission pressure/temperature sensor.
DTC P0713: TRANS TEMP SENSOR VOLTAGE TOO HIGH
Circuit Description
Circuit is monitored continuously while key is on, and engine
Page 234 of 1691
between Black PCM harness connector C1 and transmission
pressure/temperature 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, replace
transmission pressure/temperature sensor.
10) Reconnect all harness connectors. Using scan tool, read
TRANS TEMP voltage. If voltage is greater than 3.76 volts, replace
PCM. If voltage is 3.76 volts or less, conditions required to set DTC
P0713 are not present at this time. DTC P0713 sets when transmission
temperature sensor voltage at PCM is greater than 3.76 volts for 2.2
seconds. Possible causes are: open transmission temperature sensor
wiring, faulty connections, faulty transmission temperature sensor or
faulty PCM. Go to next step.
11) 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 P0720: LOW OUTPUT SPEED SENSOR RPM ABOVE 15 MPH (EXCEPT
BR BODY)
Circuit Description
Circuit is monitored continuously while key is on, and gear
selector is not in Park or Neutral. Code sets if vehicle speed is
above 15 MPH and output shaft speed is below 60 RPM for 2.6 seconds as
measured from vehicle speed sensor.
Possible Causes
* Open output speed sensor ground circuit.
* Damaged ignition wiring.
* Open output speed sensor signal circuit.
* Short to ground in output speed sensor signal circuit.
* Park/Neutral switch code present.
* Malfunctioning sensor.
* Short to ground in output speed sensor ground circuit.
* Malfunctioning PCM.
* OSS harness intermittent defective.
Diagnostic Procedure
1) Using scan tool, check SPECIFIC GOOD TRIPS counter. If DTC
SPECIFIC GOOD TRIPS counter is not displayed or displayed count is not
"0", go to step 12). If DTC SPECIFIC GOOD TRIPS counter is displayed
and displayed count is "0", go to next step.
2) Record all DTCs and one trip failures. If DTC P1899 is
present, repair P/N switch code first. See DTC P1899: P/N SWITCH STUCK
IN PARK OR ON GEAR. If DTC P1899 is not present, go to next step.
3) Raise and support vehicle. Using scan tool, erase DTCs.
See CLEARING DIAGNOSTIC TROUBLE CODES. Start engine. Place engine in
1st gear. Using scan tool, read output speed sensor. Release brake and
let wheels roll, keeping speed below 15 MPH. If scan tool shows 60 RPM
or less, go to step 6). If scan tool shows greater than 60 RPM, go to
next step.
4) While monitoring output speed sensor, wiggle harness
between output speed sensor and PCM. If reading dropped towards zero
while wiggling harness, repair intermittent short or open in harness.
If reading does not drop towards zero while wiggling harness, go to
next step.
5) Using scan tool, erase DTCs. See CLEARING DIAGNOSTIC
TROUBLE CODES. Road test vehicle. If code returns, there are no other
potential causes. Replace PCM. If code does not return, testing is
complete.
6) Turn ignition off. Disconnect PCM and output speed sensor
harness connectors and inspect for damage. Repair as necessary. If no
Page 235 of 1691
problem is found, measure resistance between output speed sensor
terminals. If resistance is 300-1200 ohms, go to next step. If
resistance is not as specified, replace output speed sensor.
7) Reconnect output speed sensor. Measure resistance between
ground and output speed sensor ground circuit at PCM harness
connector. If resistance is greater than 5 ohms, go to next step. If
resistance is not as specified, repair output speed sensor ground
circuit for a short to ground.
8) Measure resistance between ground and output speed sensor
signal circuit at PCM harness connector. If resistance is less than 5
ohms, repair output speed sensor signal circuit for a short to ground.
If resistance is not as specified, go to next step.
9) Measure resistance between output speed sensor signal
circuit and ground circuit at PCM harness connector. If resistance is
300-1200 ohms, replace PCM. If resistance is not as specified, go to
next step.
10) Disconnect output speed sensor harness connector. Measure
resistance of output speed sensor signal circuit between output speed
sensor harness connector and PCM harness connector. If resistance is
greater than 5 ohms, repair open in output speed sensor signal
circuit. If resistance is not as specified, repair open in output
speed sensor ground circuit.
11) Turn ignition on. Measure voltage between ground and
speed sensor ground circuit at PCM harness connector. Place gearshift
lever in each gear position and record voltage at each position. If
voltage is greater than one volt in any gear position, repair speed
sensor ground circuit for a short to power. If voltage is not as
specified, go to next step.
12) Raise and support vehicle. Start engine. Place gearshift
lever in "OD" position. Release brakes and allow wheels to rotate.
Using scan tool, monitor output speed sensor. While monitoring output
speed sensor, wiggle harness between output speed sensor and PCM. If
reading dropped towards zero while wiggling harness, repair
intermittent short or open in harness. If reading does not drop
towards zero while wiggling harness, problem is intermittent. See
INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is
complete.
DTC P0740: TORQ CONV CLU, NO RPM DROP AT LOCKUP
Circuit Description
Circuit is monitored continuously while key is on, and gear
selector is not in Park or Neutral. Code sets if Torque Converter
Clutch (TCC) does not achieve desired drop in RPM when TCC solenoid is\
near maximum duty cycle. A bad test 3 consecutive times is required to
set code.
Possible Causes
* Misfire trouble code set.
* Vehicle stalls (faulty TCC solenoid).
* TCC shaft seal/seal defective.
* Transmission fluid contaminated.
* TCC solenoid wiring harness defective.
* TCC defective.
* TCC hydraulic circuit damaged.
Diagnostic Procedure
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 10). If DTC SPECIFIC GOOD TRIPS counter is displayed and
displayed count is "0", indicating DTC still exists, go to next step.
Page 236 of 1691
![DODGE RAM 1999 Service Manual PDF 2) If any DTCs listed are present, perform appropriate
test(s). See TORQUE CONVERTOR CLUTCH (TCC) TESTS table. If no DTCs a\
re
present, go to next step.
TORQUE CONVERTOR CLUTCH (TCC) TESTS](/img/12/56915/w960_56915-235.png "DODGE RAM 1999 Service Manual PDF 2) If any DTCs listed are present, perform appropriate
test(s). See TORQUE CONVERTOR CLUTCH (TCC) TESTS table. If no DTCs a\
re
present, go to next step.
TORQUE CONVERTOR CLUTCH (TCC) TESTS")
2) If any DTCs listed are present, perform appropriate
test(s). See TORQUE CONVERTOR CLUTCH (TCC) TESTS table. If no DTCs a\
re
present, go to next step.
TORQUE CONVERTOR CLUTCH (TCC) TESTS
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DTC DTC Message
P0122 (1) ................. THROTTLE POSITION SENSOR VOLTAGE TOO LOW
P0123 ( 1) ................ THROTTLE POSITION SENSOR VOLTAGE TOO HIGH
P1696 ( 1) .......................... PCM FAILURE EEPROM WRITE DENIED
P0743 ........ TORQUE CONVERTOR CLUTCH SOLENOID/TRANS RELAY CIRCUITS
( 2) ........................................................ MISFIRE
P0320 ( 1) ......................... NO CRANK REFERENCE SIGNAL AT PCM
( 1) - See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
( 2) - Perform appropriate misfire DTC test. 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) Start engine. Using scan tool, perform TCC SYSTEM TEST. If
vehicle does not stall, go to step 9). If vehicle stalls, go to next
step.
5) Using scan tool, perform GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear. If vehicle stalls, go to next step. If vehicle
does not stall, go to step 7).
6) Turn ignition off. Replace TCC solenoid. Using scan tool,
perform GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear. If
vehicle stalls, problem in internal. Check for blocked passage. If
vehicle does not stall, testing is complete.
7) Turn ignition off. Remove oil pump and inspect reaction
shaft, input shaft and input seal. Repair transmission as necessary.
See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, go to next step.
8) 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.
9) Turn ignition off. Connect a pressure gauge to
transmission cooler OUT port. Start engine. Using scan tool, perform
TCC SYSTEM TEST. If pressure increases when TCC is actuated, go to
next step. If pressure does not increase, repair leaks or blockage in
hydraulic circuit, or repair valve body as necessary.
10) Turn engine off. Remove oil pump and inspect reaction
shaft, input shaft and input seal. Repair transmission as necessary.
See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, there are no other potential causes remaining.
TCC is assumed to be defective. Replace torque converter.
DTC P0743: TORQUE CONV CLUTCH SOLENOID/TRANS RELAY CKT
NOTE: To test transmission temperature sensor, engine and
transmission temperature must be less than 85F (29C).
Circuit Description
Circuit is monitored continuously while key is on. Code sets
if voltage detected on Torque Converter Clutch (TCC) at the Powertrain\
Control Module (PCM) does not match desired voltage.
Possible Causes
Page 237 of 1691
* Fused B+ feed to transmission control circuit open.
* Transmission control relay defective.
* TCC solenoid control circuit open.
* TCC solenoid control circuit shorted to ground.
* TCC wire harness defective.
* Transmission control relay output circuit open.
* Transmission control relay output circuit shorted to
ground.
* PCM defective.
* Solenoid and harness assembly defective.
Diagnostic Procedure (AN & DN Bodies)
1) Using scan tool, read DTCs. If DTC P1765 is also set, go
to DTC DTC P1765: TRANS 12-VOLT SUPPLY RELAY CNTRL CIRCUIT. If DTC
P1765 is not set, go to next step.
2) Using scan tool, perform TCC SYSTEM TEST. If engine
stalls, go to next step. If engine does not stall, go to step 5).
3) Using scan tool, clear DTCs. Start engine and check for
DTCs. Wiggle wiring harness between transmission harness connector and
PCM. If DTC P0743 resets, repair wiring harness as necessary. If DTC
P0743 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. Inspect connector and terminals for damage. Repair
as necessary. If connector and terminals are okay, turn ignition on.
Using scan tool, actuate transmission control relay. Measure voltage
between ground and transmission control relay output circuit at
transmission solenoid harness connector. If voltage does not cycle
from zero to greater than 10 volts, go to step 19). If voltage cycles
from zero to greater than 10 volts, go to next step.
6) Turn ignition off. Disconnect White PCM harness connector
C2. Inspect connector and terminals for damage. Repair as necessary.
If connector and terminals are okay, turn ignition on. Measure voltage
between ground and TCC 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 TCC solenoid control circuit for short to voltage.
Reconnect PCM and transmission solenoid harness connector. Start
engine. Using scan tool, perform TCC SYSTEM TEST. If engine stalls,
testing complete. If engine does not stall, replace PCM.
8) Reconnect transmission solenoid harness connector. Remove
transmission control relay. Inspect relay connector and terminals for
damage. Repair as necessary. If connector and terminals are okay,
measure resistance between transmission control relay output circuit
at transmission control relay connector and TCC solenoid control
circuit at White PCM harness connector C2. If resistance is 40 ohms or
less, go to step 12). If resistance is greater than 40 ohms, go to
next step.
9) Reconnect transmission control relay. Measure resistance
between ground and TCC solenoid control circuit at White PCM harness
connector C2. If resistance is less than 5 ohms, repair or replace
transmission solenoid and harness assembly. If resistance is 5 ohms or
greater, go to next step.
10) Remove transmission control relay. Measure resistance
between transmission control relay output circuit at transmission
control relay connector and TCC solenoid control circuit at White PCM
harness connector C2. If resistance is 26-40 ohms, replace PCM. If
resistance is not 26-40 ohms, go to next step.
11) Turn ignition off. Disconnect transmission solenoid
harness connector. Measure resistance of TCC solenoid control circuit