DODGE RAM 1999 Service Repair Manual
Manufacturer: DODGE, Model Year: 1999, Model line: RAM, Model: DODGE RAM 1999Pages: 1691, PDF Size: 40.34 MB
Page 391 of 1691
10.4 volts. FTC P1595 will set if vacuum and vent solenoids do not
respond when actuated by PCM.
Possible Causes:
* Ground circuit open.
* S/C brake switch output circuit open.
* S/C power supply circuit open or shorted.
* S/C servo defective.
* S/C vacuum solenoid control circuit open or shorted.
* S/C vent solenoid control circuit open or shorted.
* Brake switch defective or out of adjustment.
* Defective PCM.
NOTE: For component locations, see COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
1) Turn ignition on. Turn Speed Control (S/C) on. Using scan\
tool, actuate S/C vent solenoid. If speed control servo clicks, go to
next step. If S/C servo does not click, go to step 7).
2) Using scan tool, actuate S/C vacuum solenoid. If S/C servo
clicks, go to next step. If S/C servo does not click, go to step 6).
3) Turn ignition on. Using scan tool, actuate S/C vacuum
solenoid. Wiggle wiring harness between S/C servo and brake switch to
PCM while scan tool is still actuating speed control vacuum solenoid.
If wiggling did not cause an interruption of S/C servo actuation, go
to next step. If wiggling caused an interruption of S/C servo
actuation, repair wiring harness as necessary. Perform TEST VER-4A
under VERIFICATION TESTS.
4) Turn ignition off. Inspect S/C wiring and connectors.
Clean or repair as necessary. Perform TEST VER-4A under VERIFICATION
TESTS. If wiring and connectors are okay, go to next step.
5) Using scan tool, actuate S/C vent solenoid. Wiggle wiring
harness between S/C servo and brake switch to PCM while scan tool is
still actuating speed control vacuum solenoid. If wiggling did not
cause interruption of S/C servo actuation, test is complete. If
wiggling caused interruption of S/C servo actuation, repair wiring
harness as necessary. Perform TEST VER-4A under VERIFICATION TESTS.
6) Using scan tool, actuate S/C vent solenoid. Wiggle wiring
harness between S/C servo and brake switch to PCM while scan tool is
still actuating speed control vacuum solenoid. If wiggling did not
cause interruption of S/C servo actuation, go to next step. If
wiggling caused interruption of S/C servo actuation, repair wiring
harness as necessary. Perform TEST VER-4A under VERIFICATION TESTS.
NOTE: Ensure brake pedal is not depressed during the following
steps.
7) Turn ignition off. Disconnect S/C servo 4-pin connector.
Inspect all related wiring and connectors and repair as necessary.
Turn ignition on. Turn S/C switch on. Using a 12-volt test light,
probe brake switch output circuit at S/C servo connector terminal No.
3 (Dark Blue/Red wire). If test light is illuminated and bright, go to\
next step. If test light is dim or not illuminated, go to step 13).
8) Turn ignition off. Using an ohmmeter, check resistance of
ground circuit at S/C servo connector terminal No. 4 (Black wire). If
resistance is 5 ohms or more, repair open ground circuit. Perform TEST
VER-4A under VERIFICATION TESTS. If resistance is less than 5 ohms, go
to next step.
9) Disconnect PCM. Inspect connectors. Clean or repair as
necessary. Using an ohmmeter, measure resistance between ground and
S/C vacuum solenoid control circuit at S/C servo connector terminal
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No. 1 (Tan/Red wire). If resistance is less than 5 ohms, repair short
to ground. Perform TEST VER-4A under VERIFICATION TESTS. If resistance
is 5 ohms or more, go to next step.
10) Using an ohmmeter, check resistance between ground and
S/C vent solenoid control circuit at S/C servo connector terminal No.
2 (Light Green/Red wire). If resistance is less than 5 ohms, repair
short to ground. Perform TEST VER-4A under VERIFICATION TESTS. If
resistance is 5 ohms or more, go to next step.
11) Using an ohmmeter, measure resistance of S/C vacuum
solenoid control circuit between S/C servo connector terminal No. 1
and PCM connector C3, terminal No. 4 (Tan/Red wire). If resistance is
5 ohms or more, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, go to next
step.
12) Using an ohmmeter, check resistance of S/C vent solenoid
control circuit between S/C servo connector terminal No. 2 and PCM
connector C3, terminal No. 5 (Light Green/Red wire). If resistance is
5 ohms or more, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, replace S/C
servo. Perform TEST VER-4A under VERIFICATION TESTS.
13) Using an ohmmeter, check resistance between ground and
brake switch output circuit at S/C servo connector terminal No. 3
(Dark Blue/Red wire). If resistance is less than 5 ohms, repair short
to ground. Perform TEST VER-4A under VERIFICATION TESTS. If resistance
is 5 ohms or more, go to next step.
14) Reconnect PCM. Disconnect brake switch connector. Turn
ignition on. Turn S/C on. Using a 12-volt test light, probe S/C power
supply circuit at brake switch connector terminal No. 3 (Yellow/Red
wire). If test light is illuminated and bright, go to next step. If
test light is not illuminated or dim, go to step 17).
15) Turn ignition off. Using an ohmmeter, check resistance of
S/C brake switch output circuit between S/C servo connector terminal
No. 3 and brake switch connector terminal No. 4 (Dark Blue/Red wire).
If resistance is 5 ohms or more, repair open circuit. Perform TEST
VER-4A under VERIFICATION TESTS. If resistance is less than 5 ohms, go
to next step.
16) Check brake switch adjustment. See BRAKE SWITCH under
REMOVAL & INSTALLATION. Adjust as necessary. Perform TEST VER- 4A
under VERIFICATION TESTS. If brake switch adjustment is okay, replace
brake switch. Perform TEST VER-4A under VERIFICATION TESTS.
17) Turn ignition off. Disconnect PCM. Inspect connectors.
Clean or repair as necessary. Using an ohmmeter, measure resistance of
S/C power supply circuit between PCM connector C3, terminal No. 11 and
brake switch connector terminal No. 3 (Yellow/Red wire). If resistance\
is 5 ohms or more, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, replace PCM.
Perform TEST VER-4A under VERIFICATION TESTS.
FTC P1596: SPEED CONTROL SWITCH ALWAYS HIGH
FTC P1596 will set if an open circuit is detected in Speed
Control (S/C) switch circuit when ignition is on.
Possible Causes:
* Defective clockspring.
* S/C switch ground circuit open.
* Defective ON/OFF switch.
* Defective PCM.
* S/C switch signal circuit open or shorted to voltage.
NOTE: For component locations, see COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
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IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
1) Turn ignition on. Using scan tool, read S/C inputs. While
observing display, press S/C ON/OFF switch several times and leave on.
If scan tool displays S/C switch OFF and ON, go to next step. If scan
tool does not display OFF and ON, go to step 3).
2) Using scan tool, measure S/C switch voltage. While
observing display, wiggle wiring between S/C switch and PCM. If
voltage was more than 4.9 volts at any time during wiggling, repair
wiring as necessary. Perform TEST VER-4A under VERIFICATION TESTS. If
voltage was 4.9 volts or less during wiggling, test is complete.
3) Turn ignition off. Disconnect S/C ON/OFF switch. Inspect
connector. Clean or repair as necessary. Using an ohmmeter, measure
resistance of S/C switch ground circuit. If resistance is 5 ohms or
more, repair open ground circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, go to next
step.
4) Turn ignition on. Using a voltmeter, measure voltage on
S/C switch signal circuit. If voltage is more than 6 volts, repair
short to voltage. Perform TEST VER-4A under VERIFICATION TESTS. If
voltage is 6 volts or less, go to next step.
5) Turn ignition off. Disconnect PCM. Inspect connectors.
Clean or repair as necessary. Using an ohmmeter, measure resistance of
S/C switch signal circuit between ON/OFF switch connector and PCM
connector C3, terminal No. 32 (White/Light Green wire on Ram Van & Ram
Wagon; Red/Light Green wire on all other models). If resistance is
less than 5 ohms, go to next step. If resistance is 5 ohms or more, go
to step 7).
6) Using an ohmmeter, measure resistance across ON/OFF
switch. Resistance should be 20,300-20,700 ohms. If resistance is not
as specified, replace ON/OFF switch. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is as specified, replace PCM.
Perform TEST VER-4A under VERIFICATION TESTS.
7) Disconnect clockspring 5-pin connector. Clockspring 5-pin
connector is located behind lower steering column shroud. Inspect
connectors. Clean or repair as necessary. Using an ohmmeter, measure
resistance of S/C switch signal circuit between PCM connector C3,
terminal No. 32 and clockspring connector (White/Light Green wire on
Ram Van and Ram Wagon; Red/Light Green wire on all other models). If
resistance is 5 ohms or more, repair open circuit. Perform TEST VER-4A
under VERIFICATION TESTS. If resistance is less than 5 ohms, replace
clockspring. See appropriate AIR BAG RESTRAINT SYSTEMS article.
Perform TEST VER-4A under VERIFICATION TESTS.
FTC P1597: SPEED CONTROL SWITCH ALWAYS LOW
FTC P1597 will set if Speed Control (S/C) switch voltage is
less than 0.39 volts for 2 minutes when ignition is on and battery
voltage is more than 10.4 volts.
Possible Causes:
* S/C ON/OFF switch defective.
* S/C RESUME/ACCEL switch defective.
* S/C switch signal circuit shorted to ground.
* Defective PCM.
* Defective clockspring.
NOTE: For component locations, see COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
1) Turn ignition on. Using scan tool, read S/C switch
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voltage. If voltage is less than one volt, go to next step. If voltage
is one volt or more, condition to set FTC is not present at this time.
Test is complete.
2) While observing scan tool, disconnect S/C ON/OFF switch.
If S/C switch voltage changes to 5 volts, replace S/C ON/OFF switch.
Perform TEST VER-4A under VERIFICATION TESTS. If voltage does not
change to 5 volts, go to next step.
3) While observing scan tool, disconnect S/C RESUME/ACCEL
switch. If S/C switch voltage changes to 5 volts, replace S/C
RESUME/ACCEL switch. Perform TEST VER-4A under VERIFICATION TESTS. If
voltage does not change to 5 volts, go to next step.
4) Turn ignition off. Ensure both S/C switches are still
disconnected. Using an ohmmeter, check resistance between S/C switch
connector terminals (S/C switch signal circuit and S/C switch ground
circuit). If resistance is less than 5 ohms, repair short circuit.
Perform TEST VER- 4A under VERIFICATION TESTS. If resistance is 5 ohms
or more, go to next step.
5) Disconnect clockspring 4-pin connector. Clockspring 4-pin
connector is located behind steering wheel. Inspect connector. Clean
or repair as necessary. Using an ohmmeter, check resistance between
ground and S/C switch signal circuit at clockspring connector (Dark
Green/Red wire on all models except Ram Van and Ram Wagon; wire color
is not available for Ram Van and Ram Wagon). If resistance is less
than 5 ohms, repair short to ground. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is 5 ohms or more, go to next step.
6) Disconnect PCM. Inspect connectors. Clean or repair as
necessary. Using an ohmmeter, check resistance between ground and S/C
switch signal circuit at either S/C switch connector (Dark Green/Red
wire on all models except Ram Van and Ram Wagon; wire color is not
available for Ram Van and Ram Wagon). If resistance is less than 5
ohms, repair short to ground. Perform TEST VER-4A under VERIFICATION
TESTS. If resistance is 5 ohms or more, replace PCM. Perform TEST VER-
4A under VERIFICATION TESTS.
FTC P1683: SPEED CONTROL POWER RELAY CIRCUIT
FTC P1683 will set if Speed Control (S/C) power supply
circuit is open or shorted when S/C is turned on.
Possible Causes:
* Brake switch out of adjustment.
* S/C brake switch output circuit open or shorted.
* Defective S/C servo.
* Defective brake switch.
* S/C vacuum or vent solenoid control circuits open or
shorted.
* Defective PCM.
* Ground circuit open.
* S/C power supply circuit open.
NOTE: For component locations, see COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
NOTE: Ensure brake pedal is not depressed during the following
steps.
1) Turn ignition off. Disconnect S/C servo connector. Inspect
connector. Clean or repair as necessary. Turn ignition on. Using scan
tool, actuate S/C relay. Using a 12-volt test light, probe S/C brake
switch output circuit at S/C servo connector terminal No. 3 (Dark
Blue/Red wire). If test light is illuminated and bright, go to next
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step. If test light is dim or not illuminated, go to step 7).
2) Turn ignition off. Using an ohmmeter, check resistance of
ground circuit at S/C servo connector terminal No. 4 (Black wire). If
resistance is 5 ohms or more, repair open ground circuit. Perform TEST
VER-4A under VERIFICATION TESTS. If resistance is less than 5 ohms, go
to next step.
3) Disconnect PCM. Inspect connectors. Clean or repair as
necessary. Using an ohmmeter, measure resistance of S/C vacuum
solenoid control circuit between PCM connector C3, terminal No. 4 and
S/C servo connector terminal No. 1 (Tan/Red wire). If resistance is 5
ohms or more, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, go to next
step.
4) Using an ohmmeter, check resistance between ground and S/C
vacuum solenoid control circuit at S/C servo connector terminal No. 1
(Tan/Red wire). If resistance is less than 5 ohms, repair short to
ground. Perform TEST VER-4A under VERIFICATION TESTS. If resistance is
5 ohms or more, go to next step.
5) Using an ohmmeter, check resistance of S/C vent solenoid
control circuit between PCM connector C3, terminal No. 5 and S/C servo
connector terminal No. 2 (Light Green/Red wire). If resistance is 5
ohms or more, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, go to next
step.
6) Using an ohmmeter, check resistance between ground and S/C
vent solenoid control circuit at S/C servo connector terminal No. 2
(Light Green/Red wire). If resistance is less than 5 ohms, repair
short to ground. Perform TEST VER-4A under VERIFICATION TESTS. If
resistance is 5 ohms or more, replace S/C servo. Perform TEST VER-4A
under VERIFICATION TESTS.
7) Turn ignition off. Disconnect brake switch connector.
Inspect connectors. Clean or repair as necessary. Turn ignition on.
Using scan tool, actuate S/C solenoid. Using a 12-volt test light,
probe S/C power supply circuit at brake switch connector terminal No.
4 (Yellow/Red wire). If test light is illuminated and bright, go to
next step. If test light is not illuminated or dim, go to step 10).
8) Check brake switch adjustment. See BRAKE SWITCH under
REMOVAL & INSTALLATION. Adjust as necessary. Perform TEST VER- 4A
under VERIFICATION TESTS. If brake switch adjustment is okay, go to
next step.
9) Using an ohmmeter, check resistance of brake switch output
circuit between brake switch connector terminal No. 3 and S/C servo
connector terminal No. 3 (Dark Blue/Red wire). If resistance is more
than 5 ohms, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is 5 ohms or less, replace brake
switch. Perform TEST VER-4A under VERIFICATION TESTS.
10) Turn ignition off. Using an ohmmeter, check resistance
between ground and S/C brake switch output circuit at S/C servo
connector terminal No. 3 (Dark Blue/Red wire). If resistance is less
than 5 ohms, repair short to ground. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is 5 ohms or more, go to next step.
11) Disconnect PCM. Inspect connectors. Clean or repair as
necessary. Using an ohmmeter, check resistance of S/C power supply
circuit between PCM connector C3, terminal No. 11 and brake switch
connector terminal No. 4 (Yellow/Red wire). If resistance is 5 ohms or\
more, repair open circuit. Perform TEST VER-4A under VERIFICATION
TESTS. If resistance is less than 5 ohms, replace PCM. Perform TEST
VER-4A under VERIFICATION TESTS.
FTC P1899: PARK/NEUTRAL POSITION (PNP) SWITCH STUCK IN PARK
OR IN GEAR (A/T MODELS)
Possible Causes:
Page 396 of 1691
* PNP switch defective.
* PNP switch sense circuit open or shorted.
* PNP switch stuck.
* PCM defective.
NOTE: For component locations, see COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
1) Turn ignition on. Using scan tool, read PNP switch state.
While observing scan tool, move gear selector between Park and
Reverse. If scan tool displays P/N and D/R, go to next step. If scan
tool does not display P/N and D/R, go to step 3).
2) Turn ignition off. Inspect wiring and connectors related
to PNP switch. Repair as necessary. Perform TEST VER-5A under
VERIFICATION TESTS. If wiring and connectors are okay, condition to
set FTC is not present at this time. Test is complete. Use freeze
frame data to determine conditions when FTC was set.
3) Turn ignition off. Disconnect PCM. Inspect connectors.
Clean or repair as necessary. Using an ohmmeter, check resistance
between ground and PNP switch sense circuit at PCM connector C1,
terminal No. 6 (Black/White wire). While observing ohmmeter, move gear\
selector from Park to Reverse and back to Park. If resistance switched
from less than 10 ohms to more than 10 ohms, replace PCM. Perform TEST
VER-5A under VERIFICATION TESTS. If resistance was less than 10 ohms
at all times, go to next step. If resistance was more than 10 ohms at
all times, go to step 5).
4) Disconnect PNP switch. Inspect connectors. Clean or repair
as necessary. Using an ohmmeter, check resistance between ground and
PNP switch sense circuit. If resistance is less than 5 ohms, repair
short to ground. Perform TEST VER-5A under VERIFICATION TESTS. If
resistance is 5 ohms or more, repair or replace stuck PNP switch.
Perform TEST VER-5A under VERIFICATION TESTS.
5) Using an ohmmeter, check resistance of PNP switch circuit
between PNP switch connector and PCM connector C1, terminal No. 6
(Black/White wire). If resistance is 5 ohms or more, repair open
circuit. Perform TEST VER-5A under VERIFICATION TESTS. If resistance
is less than 5 ohms, replace PNP switch. Perform TEST VER-5A under
VERIFICATION TESTS.
SYSTEM TESTS
NOTE: For component locations, See COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
CHECKING SPEED CONTROL OPERATION
NOTE: Perform this test only if there are no DTCs.
1) Turn ignition on. Using scan tool, monitor S/C switch
inputs. Press S/C ON/OFF switch several times. If scan tool displays
speed control switch on and off, go to next step. If scan tool does
not display speed control switch on and off, go to NTC-3: SPEED
CONTROL ON/OFF SWITCH.
2) While observing scan tool, press RESUME/ACCEL switch
several times. If scan tool displays RESUME/ACCEL switch PRESSED and
RELEASED, go to next step. If scan tool does not display PRESSED and
RELEASED, go to NTC-4: SPEED CONTROL RESUME/ACCEL SWITCH.
3) While observing scan tool, press brake pedal several
times. If scan tool displays brake pedal PRESSED and RELEASED, go to
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next step. If scan tool does not display brake pedal PRESSED and
RELEASED, go to NTC-1: BRAKE SWITCH SENSE.
4) Turn S/C on. On A/T models, move gear selector to Drive.
If scan tool displays park neutral switch D/R, go to next step. If
scan tool does not display park neutral switch D/R, go to FTC P1899:
PARK/NEUTRAL POSITION SWITCH STUCK IN PARK OR IN GEAR under DIAGNOSTIC
TESTS.
5) On all models, using scan tool, actuate S/C vent solenoid.
Using a 12-volt test light, backprobe S/C brake switch output circuit
at S/C servo connector terminal No. 3 (Dark Blue/Red wire). If test
light is illuminated and bright, go to next step. If test light is dim
or is not illuminated, go to NTC-1: BRAKE SWITCH SENSE.
6) Start engine and let idle for one minute. Turn engine off.
Turn ignition on (engine off). Using scan tool, actuate S/C servo
solenoids. If throttle opens and closes, go to NTC-2: CHECKING FOR
SPEED CONTROL DENIED MESSAGE. If throttle does not open and close,
inspect throttle cable and linkage. Check vacuum supply. See VACUUM
SUPPLY under COMPONENT TESTS. Repair as necessary. Perform TEST VER-4A
under VERIFICATION TESTS.
7) While observing scan tool, press CANCEL switch several
times. If scan tool displays PRESSED and RELEASED, go to next step. If
scan tool does not display PRESSED and RELEASED, replace CANCEL
switch. Perform TEST VER-4A under VERIFICATION TESTS.
8) Turn ignition off. Disconnect S/C servo connector. Using
an ohmmeter, check resistance of ground circuit at S/C servo connector
terminal No. 4 (Black wire). If resistance is 5 ohms or more, repair
open ground circuit. Perform TEST VER-4A under VERIFICATION TESTS. If
resistance is less than 5 ohms, go to next step.
9) Reconnect S/C servo connector. Turn ignition and S/C on.
While observing scan tool, press SET switch several times. If scan
tool displays PRESSED and RELEASED, go to next step. If scan tool does
not display PRESSED and RELEASED, replace SET switch. Perform TEST
VER-4A under VERIFICATION TESTS.
10) Turn ignition off. Disconnect S/C servo connector.
Inspect terminals. If any terminal is damaged, pushed out or miswired,
repair as necessary. Perform TEST VER-4A under VERIFICATION TESTS. If
terminals are okay, go to next step.
11) Disconnect S/C servo connector. Disconnect PCM
connectors. Inspect connectors. Clean or repair as necessary. Using an
ohmmeter, check resistance of S/C vacuum solenoid control circuit
between PCM connector C3, terminal No. 4 and S/C servo connector
terminal No. 1 (Tan/Red wire). If resistance is 5 ohms or more, repair\
open circuit. Perform TEST VER-4A under VERIFICATION TESTS. If
resistance is less than 5 ohms, go to next step.
12) Turn S/C on. While observing scan tool, press COAST
switch several times. If scan tool displays PRESSED and RELEASED, go
to next step. If scan tool does not display PRESSED and RELEASED,
replace COAST switch. Perform TEST VER-4A under VERIFICATION TESTS.
13) Using an ohmmeter, check resistance of S/C vent solenoid
control circuit between PCM connector C3, terminal No. 5 and S/C servo
connector terminal No. 2 (Light Green/Red wire). If resistance is 5
ohms or more, repair open circuit. Perform TEST VER-4A under
VERIFICATION TESTS. If resistance is less than 5 ohms, replace S/C
servo. Perform TEST VER-4A under VERIFICATION TESTS.
NTC-1: BRAKE SWITCH SENSE
Possible Causes:
* Ground circuit open.
* Defective brake switch.
* Brake switch sense circuit open or shorted.
* Defective PCM.
Page 398 of 1691
1) Turn ignition off. Disconnect brake switch connector.
Inspect connector. Clean or repair as necessary. Turn ignition on.
Using a voltmeter, measure voltage of brake switch sense circuit at
brake switch White/Pink wire. If voltage is more than 10 volts, go to
next step. If voltage is 10 volts or less, go to step 3).
2) Connect a jumper wire between ground and brake switch
connector White/Pink wire. Using scan tool, read brake switch input
status. If scan tool displays brake switch released, replace brake
switch. Perform TEST VER-4A under VERIFICATION TESTS. If scan tool
does not display brake switch released, repair open ground circuit.
Perform TEST VER-4A under VERIFICATION TESTS.
3) Disconnect PCM connectors. Inspect connectors. Clean or
repair as necessary. Using an ohmmeter, measure resistance between
ground and brake switch sense circuit at PCM connector C3, terminal
No. 24 (White/Pink wire). If resistance less than 5 ohms, repair short\
to ground. Perform TEST VER-4A under VERIFICATION TESTS. If resistance
is 5 ohms or more, go to next step.
4) Using an ohmmeter, measure resistance of brake switch
sense circuit between PCM connector C3, terminal No. 24 and brake
switch White/Pink wire. If resistance is 5 ohms or more, repair open
brake switch sense circuit. Perform TEST VER-4A under VERIFICATION
TESTS. If resistance is less than 5 ohms, replace PCM. Perform TEST
VER-4A under VERIFICATION TESTS.
NTC-2: CHECKING FOR SPEED CONTROL DENIED MESSAGE
At this time speed control switch and servo functions appear
to operate properly. Using scan tool, monitor speed control output
status. Road test vehicle at speeds more than 30 MPH. Attempt to set
speed control. See SCAN TOOL DENIED STATUS table. Items listed in
table will not allow speed control to set. The last or most recent
cause for speed control not to set is indicated by denied status.
Correct fault and recheck system operation.
SCAN TOOL DENIED STATUS
\
\
\
\
\
\
\
Denied Message Reason
\
\b \
\
\
\
\
\
ON/OFF PCM Does Not See An ON Signal From Switch
At PCM Terminal No. 41
\
\b \
\
\
\
\
\
SPEED Vehicle Speed As Seen By PCM Terminal
No. 66 Is Not Greater Than 36 MPH
\
\b \
\
\
\
\
\
RPM Engine RPM Is Excessively High
\
\b \
\
\
\
\
\
BRAKE Brake Switch Sense Circuit Is Open
Indicating That Brakes Are Applied
\
\b \
\
\
\
\
\
P/N Park/Neutral Switch Sense Circuit Is Grounded
Indicating That Transmission Is In Park Or Neutral
\
\b \
\
\
\
\
\
RPM/SPD PCM Senses Excessive Engine RPM
For A Given Vehicle Speed
\
\b \
\
\
\
\
\
SOL FLT PCM Senses A Servo Solenoid Circuit
Trouble Code That Is Maturing Or Set In Memory
\
\
\
\
\
\
\
\f
NTC-3: SPEED CONTROL ON/OFF SWITCH
Possible Causes:
Page 399 of 1691
* Signal circuit open or shorted.
* S/C ON/OFF switch defective.
* S/C RESUME/ACCEL switch defective.
* Defective PCM.
* Defective clockspring.
1) Turn ignition on. Using scan tool, read S/C switch
voltage. If voltage is more than 4 volts, go to next step. If voltage
is 4 volts or less, go to step 4).
2) Turn ignition off. Disconnect S/C ON/OFF switch. Inspect
connector. Clean or repair as necessary. Connect a jumper wire between
ground and S/C switch signal circuit at S/C ON/OFF switch connector
(Dark Green/Red wire on all models except Ram Van and Ram Wagon; wire
color is not available for Ram Van and Ram Wagon). Turn ignition on.
Using scan tool, read S/C switch voltage. If voltage is less than one
volt, replace S/C ON/OFF switch. Perform TEST VER-4A under
VERIFICATION TESTS. If voltage is one volt or more, go to next step.
3) Using a voltmeter, measure voltage on S/C switch signal
circuit. If voltage is less than 4 volts, repair high resistance in
S/C switch signal circuit. Perform TEST VER-4A under VERIFICATION
TESTS. If voltage is more than 6 volts, repair short to voltage.
Perform TEST VER-4A under VERIFICATION TESTS. If voltage is 4-6 volts,
replace PCM. Perform TEST VER-4A under VERIFICATION TESTS.
4) Turn ignition off. Disconnect S/C ON/OFF switch.
Disconnect PCM. Inspect connectors. Clean or repair as necessary.
Using an ohmmeter, measure resistance between ground and S/C switch
signal circuit at PCM connector C3, terminal No. 32 (White/Light Green
wire on Ram Van & Ram Wagon; Red/Light Green wire on all other
models). If resistance is less than 5 ohms, repair short to ground.
Perform TEST VER-4A under VERIFICATION TESTS. If resistance is 5 ohms
or more, go to next step.
5) Reconnect PCM. Ensure S/C ON/OFF switch is still
disconnected. Turn ignition on. Using scan tool, read S/C switch
voltage. If voltage is more than 4 volts, replace ON/OFF switch.
Perform TEST VER-4A under VERIFICATION TESTS. If voltage is 4 volts or
less, go to next step.
6) Disconnect RESUME/ACCEL switch. Using scan tool, read S/C
switch voltage. If voltage is more than 4 volts, replace RESUME/ACCEL
switch. Perform TEST VER-4A under VERIFICATION TESTS. If voltage is 4
volts or less, go to next step.
7) Disconnect clockspring connector located behind lower
steering column shroud. Inspect connector. Clean or repair as
necessary. Using scan tool, read S/C switch voltage. If voltage is
more than 4 volts, replace clockspring. See AIR BAG RESTRAINT SYSTEMS
- TRUCKS article. Perform TEST VER-4A under VERIFICATION TESTS. If
voltage is 4 volts or less, test is complete.
NTC-4: SPEED CONTROL RESUME/ACCEL SWITCH
Possible Causes:
* Ground circuit open.
* RESUME/ACCEL switch defective.
* Signal circuit open.
1) Turn ignition off. Disconnect RESUME/ACCEL switch. Inspect
connectors. Clean or repair as necessary. Connect a jumper wire
between ground and S/C switch signal circuit at RESUME/ACCEL switch
connector (Dark Green/Red wire on all models except Ram Van and Ram
Wagon; wire color is not available for Ram Van and Ram Wagon). Turn
ignition on. Using scan tool, read S/C switch voltage. If voltage is
less than one volt, replace RESUME/ACCEL switch. Perform TEST VER-4A
Page 400 of 1691
under VERIFICATION TESTS. If voltage is one volt or more, go to next
step.
2) Turn ignition off. Using an ohmmeter, check resistance of
RESUME/ACCEL switch ground circuit at RESUME/ACCEL switch connector.
If resistance is 5 ohms or more, repair open ground circuit. Perform
TEST VER-4A under VERIFICATION TESTS. If resistance is less than 5
ohms, repair open S/C switch signal circuit. Perform TEST VER-4A under
VERIFICATION TESTS.
VERIFICATION TESTS
TEST VER-4A
NOTE: If PCM has been replaced and correct VIN and mileage have not
been programmed, a FTC will be set in ABS and air bag
modules. If vehicle is equipped with a Sentry Key Immobilizer
Module (SKIM), sentry key data must be updated to enable
starting. See COMPUTER RELEARN PROCEDURES article in GENERAL
INFORMATION.
1) If vehicle is not equipped with a diesel engine, go to
next step. If vehicle is equipped with a diesel engine, and PCM has
been disconnected or replaced, battery has been disconnected, or
Accelerator Pedal Position Sensor (APPS) has been disconnected or
replaced, APPS calibration must be programmed into PCM (diesel only).
Turn ignition on. Slowly press accelerator pedal to floor and slowly
release. DO NOT attempt to adjust screws or disassemble APPS. Go to
next step.
2) On all engines, if vehicle is equipped with ABS or air
bag, enter correct VIN and mileage in PCM. Erase DTCs in ABS and air
bag modules. Inspect vehicle to ensure all engine and speed control
system components are connected. Reassemble and reconnect components
as necessary. Using scan tool, erase DTCs from PCM.
3) Road test vehicle at a speed greater than 35 MPH. Turn S/C
switch on. Press and release SET button. If S/C does not engage,
repair is not complete. Check for related TSBs and return to TROUBLE
SHOOTING, if necessary. If speed control engages, go to next step
4) Quickly depress and release RESUME/ACCEL switch. If
vehicle speed increases by 2 MPH, go to next step. If vehicle speed
does not increase by 2 MPH, repair is not complete. Check for related
TSBs and return to TROUBLE SHOOTING, if necessary.
5) Press and hold COAST switch. Vehicle speed should
decrease. If vehicle speed decreases, go to next step. If vehicle
speed does not decrease, repair is not complete. Check for related
TSBs and return to TROUBLE SHOOTING, if necessary.
6) Using caution, depress and release brake pedal. If S/C
disengages, go to next step. If S/C does not disengage, repair is not
complete. Check for related TSBs and return to TROUBLE SHOOTING, if
necessary.
7) Bring vehicle speed to 35 MPH. Depress speed control
RESUME/ACCEL switch. If vehicle resumes to previously set speed, go to
next step. If vehicle does not resume to previously set speed, repair
is not complete. Check for related TSBs and return to TROUBLE
SHOOTING, if necessary.
8) Hold down SET switch. Vehicle speed should decrease. If
vehicle speed decreases, go to next step. If vehicle speed did not
decrease, repair is not complete. Check for related TSBs and return to
TROUBLE SHOOTING, if necessary.
9) Ensure vehicle speed is more than 35 MPH and release SET
switch. If vehicle sets a new speed, go to next step. If vehicle did
not set a new speed, repair is not complete. Check for related TSBs
and return to TROUBLE SHOOTING, if necessary.