brake DODGE RAM SRT-10 2006 Service Owner's Guide

When Monitored:
Ignition on.
Set Condition:
The PCM doesn’t receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus. One
Trip fault.
Possible Causes
CAN C BUS CIRCUIT OPEN OR SHORTED
ANTI-LOCK BRAKE MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING) .
Theory of Operation
The PCM receives the vehicle speed signal over the CAN C bus from the Anti-lock Brake Module.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With the scan tool read Powertrain DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.U0121-LOST COMMUNICATION WITH ABS MODULE ALSO SET
With the scan tool continue reading DTCs.
Is the U0121-LOST COMMUNICATION WITH ABS MODULE also set?
Ye s>>
Follow the diagnostics for U0121-LOST COMMUNICATION WITH ABS MODULE
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1417-IMPLAUSIBLE LEFT WHEEL DISTANCE SIGNAL RECEIVED active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 3
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
3.DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Ye s>>
Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1
No>>
Go to 4

When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1418-IMPLAUSIBLE RIGHT WHEEL DISTANCE SIGNAL RECEIVED active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 3
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
3.DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Ye s>>
Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1
No>>
Go to 4

3.EXCESSIVE RESISTANCE IN THE BATTERY CIRCUIT
Turn the ignition off.
Check the Battery Cables for excessive resistance using the service information procedure.
Did either Battery Cable have a voltage drop greater than 0.2 of a volt?
Ye s>>
Repair the excessive resistance in the Battery circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.STARTER RELAY
Turn ignition off.
Remove the Starter Relay from IPM.
CAUTION: The Parking Brake must be on and the Transmission must be in park for a vehicle equipped with
an automatic transmission.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Briefly connect a jumper wire from the Internal Fused B+ circuit to the (T750) Starter Relay Output circuit.
Did the Starter Motor crank the engine?
Ye s>>
Go To 5
No>>
Go To 7
5.(T751) FUSED IGNITION SWITCH OUTPUT CIRCUIT
Ignition on, engine not running.
Using a 12-volt test light, probe the (T751) Fused Ignition Switch Output circuit in the Starter Relay connector.
While observing 12-volt test light, hold ignition key in the start position.
Does the test light illuminate brightly?
Ye s>>
Go To 6
No>>
Repair the excessive resistance in the(T751)FusedIgnitionSwitchOutput circuit. Inspect related fuses
and repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

POWERTRAIN VERIFICATION TEST
For a complete wiring diagramRefer to Section 8W.
Diagnostic Test
1.SELECTING THE PROPER VERIFICATION TEST
The following verification test are for different repairs. Select the appropriate Verification test for the
repair that has been completed.
Speed Control repair
Go To 2
Charging System repair
Go To 3
NVLD System repair
Go To 4
All other repairs
Go To 5
2.POWERTRAIN VERIFICATION TEST 1
NOTE: 1. If this vehicle is equipped with an Electronic Throttle Control system, and the APP Sensors, PCM,
or Throttle Body Assembly have been replaced, use the scan tool to perform the ETC RELEARN function.
NOTE: 2. After completing the Powertrain Verification Test the Transmission Verification Test must be per-
formed.
NOTE: 3. If the PCM has been replaced and the correct VIN and mileage have notbeen programmed, a DTC
will set in the ABS Module, Airbag Module and the SKIM/SKREEM.
NOTE: 4. If the vehicle is equipped with a Sentry Key Remote Entry, Secret Key data must be updated. Refer
to the Service Information for the PCM, SKIM/SKREEM and the Transponder (ignition key) for programming
information. Using the scan tool, program the Secret Key information intothe PCM using the PCM replaced
function under the WCM menu.
5. Inspect the vehicle to make sure that all engine components are properlyinstalled and connected.
6. Connect the scan tool to the data link connector and erase all codes.
7. Turn the speed control ON (if equipped, cruise light will be on).
8. Depress and release the SET Switch when the vehicle speed is greater than35 MPH. The speed control should
engage and hold the selected speed.
9. Press and hold the RESUME/ACCEL Switch. The vehicle speed should increase by at least 2 MPH.
10. Press and hold the COAST switch. The vehicle speed should decrease.
11. Using caution, press and release the brake pedal. The speed control should disengage.
12. Bring the vehicle speed back up to 35 MPH.
13. Press the RESUME/ACCEL switch. The speed control should resume the previously set speed.
14. Hold down the SET switch. The vehicle should decelerate.
15. Make sure vehicle speed is greater than 35 mph and release the SET Switch. The vehicle should adjust and set
a new vehicle speed.
16. Press and release the CANCEL switch. The speed control should disengage.
17. Bring the vehicle speed back up above 35 mph and engage speed control.
18. Turn the Speed Control Off. (Cruise light will be off). The speed control should disengage.
NOTE: OVERSHOOT/UNDERSHOOT FOLLOWING SPEED CONTROL SET.
19. If the vehicle operator repeatedly presses and releases the SET buttonwith their foot off of the accelerator
(referred to as
lift foot set), the vehicle may accelerate and exceed the desired set speed by up to 5 mph (8km/h).
20. It may also decelerate to less than the desired set speed, before finally achieving the desired set speed.
21. The Speed Control System has an adaptive strategy that compensates forvehicle-to-vehicle variations in speed
control cable lengths.
22. When the speed control is set with the vehicles operators foot off of theaccelerator pedal, the speed control
thinks there is excessive speed control cable slack and adapts accordingly.

page page
ENGINE - ELECTRICAL DIAGNOSTICS -
DIESEL
DIAGNOSIS AND TESTING
PRE-DIAGNOSTIC TROUBLESHOOTING
PROCEDURE............................. 1150
POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL)................................. 1152
POWERTRAIN VERIFICATION TEST VER - 2
(DIESEL)................................. 1153
POWERTRAIN VERIFICATION TEST VER - 4
(DIESEL)................................. 1154
POWERTRAIN VERIFICATION TEST VER - 5
(DIESEL)................................. 1156
INTERMITTENT CONDITION ............... 1157
P0016-ENGINE SPEED SIGNAL MISMATCH . 1158
P0069-BOOST KEY ON RATIONALITY ...... 1160
P0071-INLET AIR TEMP SENSOR
RATIONALITY............................ 1163
P0072-INLET AIR TEMP SENSOR VOLTAGE
TOO LOW................................ 1165
P0073-INLET AIR TEMP SENSOR VOLTAGE
TOO HIGH............................... 1169
P0088-FUEL RAIL PRESSURE SIGNAL IS
ABOVE MAX LIMIT........................ 1174
P0106-INLET AIR PRESSURE SENSOR
RATIONALITY............................ 1176
P0107-INLET AIR PRESSURE SENSOR
VOLTAGE TOO LOW...................... 1178
P0108-INLET AIR PRESSURE SENSOR
VOLTAGE TOO HIGH...................... 1183
P0111-INTAKE AIR TEMPERATURE (IAT)
SENSOR RATIONALITY................... 1188
P0112-INTAKE AIR TEMPERATURE (IAT)
SENSOR VOLTAGE TOO LOW............. 1190
P0113-INTAKE AIR TEMPERATURE (IAT)
SENSOR VOLTAGE TOO HIGH............. 1195
P0116-ENGINE COOLANT TEMPERATURE
(ECT) SENSOR RATIONALITY............. 1200
P0117-ENGINE COOLANT TEMPERATURE
(ECT) SENSOR VOLTAGE TOO LOW....... 1202
P0118-ENGINE COOLANT TEMPERATURE
(ECT) SENSOR VOLTAGE TOO HIGH...... 1206
P0128-THERMOSTAT RATIONALITY ........ 1211
P0148-HIGH PRESSURE COMMON RAIL
(HPCR) CHECKSUM...................... 1212
P0169-WATER IN FUEL (WIF) LIGHT ON
TOO LONG............................... 1215
P0191-FUEL RAIL PRESSURE SENSOR
PERFORMANCE.......................... 1217
P0192-FUEL PRESSURE SENSOR
VOLTAGE TOO LOW...................... 1219P0193-FUEL PRESSURE SENSOR
VOLTAGE TOO HIGH...................... 1224
P0201-INJECTOR #1 CONTROL CIRCUIT . . . 1229
P0202-INJECTOR #2 CONTROL CIRCUIT . . . 1233
P0203-INJECTOR #3 CONTROL CIRCUIT . . . 1237
P0204-INJECTOR #4 CONTROL CIRCUIT . . . 1241
P0205-INJECTOR #5 CONTROL CIRCUIT . . . 1245
P0206-INJECTOR #6 CONTROL CIRCUIT . . . 1249
P0217-DECREASED ENGINE
PERFORMANCE DUE TO ENGINE
OVERHEAT CONDITION................... 1253
P0219-CRANKSHAFT POSITION SENSOR
OVER SPEED SIGNAL.................... 1255
P0234-TURBOCHARGER OVERBOOST
CONDITION.............................. 1257
P0236-MAP SENSOR TOO HIGH
TOO LONG............................... 1259
P0237-MAP SENSOR VOLTAGE TOO LOW . 1261
P0238-MAP SENSOR VOLTAGE TOO HIGH . 1266
P0243-WASTEGATE PRESSURE CONTROL
PWM.................................... 1271
P0251-CP3 PUMP REGULATOR CONTROL . 1277
P0299-BOOST IN RANGE LOW ............ 1283
P0300-MULTIPLE CYLINDER MISFIRE ..... 1286
P0301-CYLINDER # 1 MISFIRE ............ 1289
P0302-CYLINDER # 2 MISFIRE ............ 1292
P0303-CYLINDER # 3 MISFIRE ............ 1295
P0304-CYLINDER # 4 MISFIRE ............ 1298
P0305-CYLINDER # 5 MISFIRE ............ 1301
P0306-CYLINDER # 6 MISFIRE ............ 1304
P0335-CRANKSHAFT POSITION (CKP)
LOST.................................... 1307
P0336-CRANKSHAFT POSITION (CKP)
SENSOR SIGNAL......................... 1313
P0337-CRANKSHAFT POSITION (CKP)
SENSOR VOLTAGE TOO LOW............. 1319
P0338-CRANKSHAFT POSITION (CKP)
SENSOR VOLTAGE TOO HIGH............ 1322
P0340-CAMSHAFT POSITION (CMP) LOST . 1324
P0341-CAMSHAFT POSITION (CMP)
SENSOR SIGNAL......................... 1330
P0381-WAIT TO START LAMP
INOPERATIVE............................ 1336
P0461-FUEL LEVEL UNIT NO CHANGE
OVER TIME.............................. 1338
P0462-LOW VOLTAGE DETECTED AT THE
FUEL LEVEL SENSOR.................... 1341
P0463-HIGH VOLTAGE DETECTED AT THE
FUEL LEVEL SENSOR.................... 1345
P0477-LOW VOLTAGE ON THE ENGINE
BRAKE DRIVER.......................... 1348

P0478-HIGH VOLTAGE ON THE ENGINE
BRAKE DRIVER.......................... 1350
P0480-FAN CLUTCH ...................... 1352
P0483-FAN SPEED ....................... 1357
P0500-NO VEHICLE SPEED SENSOR
SIGNAL.................................. 1364
P0513-SKIM INVALID KEY ERROR ......... 1368
P0514-BAT TEMPERATURE SENSOR
RATIONALITY............................ 1370
P0516-LOW VOLTAGE AT THE BAT TEMP
SENSOR................................. 1372
P0517-HIGH VOLTAGE AT THE BAT TEMP
SENSOR................................. 1376
P0521-OIL PRESSURE SWITCH
RATIONALITY............................ 1380
P0524-OIL PRESSURE TOO LOW .......... 1383
P0532-A/C SENDING UNIT VOLTS TOO
LOW..................................... 1385
P0533-A/C SENDING UNIT VOLTS TOO
HIGH.................................... 1391
P0541-LOW VOLTAGE ON THE #1 INTAKE
AIR HEATER RELAY...................... 1396
P0542-HIGH VOLTAGE ON THE #1 INTAKE
AIR HEATER RELAY...................... 1399
P0562-BATTERY VOLTAGE LOW ........... 1402
P0563-BATTERY VOLTAGE HIGH .......... 1406
P0572-LOW VOLTAGE DETECTED AT THE
BRAKE SWITCH.......................... 1409
P0573-HIGH VOLTAGE DETECTED AT THE
BRAKE SWITCH.......................... 1413
P0580-LOW VOLTAGE DETECTED AT THE
SPEED CONTROL SWITCH................ 1416
P0581-HIGH VOLTAGE DETECTED AT THE
SPEED CONTROL SWITCH................ 1420
P0602-CHECKSUM ERROR ............... 1425
P0604-ECM SOFTWARE ERROR .......... 1426
P0606-ECM HARDWARE ERROR .......... 1427
P0607-ECM INTERNAL FAILURE ........... 1428
P0622-GENERATOR FIELD NOT
SWITCHING PROPERLY.................. 1429
P0628-LOW VOLTAGE DETECTED AT THE
FUEL LIFT PUMP......................... 1433
P0629-HIGH VOLTAGE DETECTED AT THE
FUEL LIFT PUMP......................... 1436
P0630-VIN NOT ENTERED ERROR ........ 1439
P0633-SKIM SECRET KEY NOT ENTERED . 1440
P0642-LOW VOLTAGE AT THE #2 SENSOR
SUPPLY CIRCUIT......................... 1441
P0643-HIGH VOLTAGE AT THE #2 SENSOR
SUPPLY CIRCUIT......................... 1445
P0646-LOW VOLTAGE DETECTED AT THE
A/C CLUTCH RELAY...................... 1448
P0647-HIGH VOLTAGE DETECTED AT THE
A/C CLUTCH RELAY...................... 1451
P0652-LOW VOLTAGE AT THE #1 SENSOR
SUPPLY CIRCUIT......................... 1454
P0653-HIGH VOLTAGE AT THE #1 SENSOR
SUPPLY CIRCUIT......................... 1458P0698-ACCELERATOR PEDAL POSITION
SENSOR (APPS) SUPPLY VOLTAGE TOO
LOW..................................... 1461
P0699-ACCELERATOR PEDAL POSITION
SENSOR (APPS) SUPPLY VOLTAGE TOO
HIGH.................................... 1465
P1272-A/C CLUTCH CONTROL CIRCUIT 2
LOW..................................... 1468
P1273-A/C CLUTCH CONTROL CIRCUIT 2
HIGH.................................... 1471
P1274-A/C CLUTCH CONTROL CIRCUIT 2
OPEN.................................... 1475
P1275-A/C CLUTCH CONTROL CIRCUIT 2
OVERCURRENT.......................... 1479
P127C-FUEL PUMP CONTROL CIRCUIT 2
LOW..................................... 1482
P127D-FUEL PUMP CONTROL CIRCUIT 2
HIGH.................................... 1485
P127E-FUEL PUMP CONTROL CIRCUIT 2
OPEN (TIPM)............................. 1489
P0127F-FUEL PUMP CONTROL CIRCUIT 2
OVERCURRENT (TIPM)
................... 1493
P1652-J1850 SHORT TO GROUND ......... 1496
P2121-PPS CONFORMANCE ERROR ...... 1499
P2122-PPS 1 VOLTAGE TOO LOW ......... 1511
P2123-PPS 1 VOLTAGE TOO HIGH ........ 1516
P2127-PPS 2 VOLTAGE TOO LOW ......... 1520
P2128-PPS 2 VOLTAGE TOO HIGH ........ 1525
P2146-BANK 1 (CYLINDERS 1-3) SHORTED
HIGH OR LOW........................... 1529
P2149-BANK 2 (CYLINDERS 4-6) SHORTED
HIGH OR LOW........................... 1537
P2266-WATER IN FUEL (WIF) SENSOR
VOLTAGE TOO LOW...................... 1544
P2269-WATER IN FUEL (WIF) .............. 1547
P2502-CHARGING SYSTEM ERROR ....... 1549
P2503-CHARGING SYSTEM OUTPUT LOW . 1552
P2504-CHARGING SYSTEM OUTPUT HIGH . 1555
P2509-POWERDOWN DATA LOST ERROR . 1559
P2607-LOW VOLTAGE AT THE #2 INTAKE
AIR HEATER RELAY...................... 1563
P2608-HIGH VOLTAGE AT THE #2 INTAKE
AIR HEATER RELAY...................... 1566
P2609-NO VOLTAGE DROP SEEN FROM
INTAKE AIR HEATERS.................... 1569
*CHECKING THE ACCELERATOR PEDAL
SENSOR CALIBRATION................... 1572
*CHECKING THE ECM POWER AND
GROUNDS............................... 1573
* PRESSURE LIMITING VALVE TEST ....... 1574
*ENGINE SURGES ........................ 1575
*ENGINE NO START/HARD START ......... 1578
*FUEL HEATER THERMOSTAT TEST ....... 1581
*IN-TANK FUEL LIFT PUMP FLOW/
DIAGNOSTIC TEST PROCEDURE.......... 1582
*FUEL PUMP RETURN FLOW TEST ........ 1585
*HIGH PRESSURE FUEL PUMP
PERFORMANCE TEST.................... 1586
*INJECTOR RETURN FLOW TEST ......... 1587

*INTAKE AIR SYSTEM PRESSURE TEST . . . 1588
U0001-CAN C BUS ....................... 1589
U0121-LOST COMMUNICATION WITH
ANTI-LOCK BRAKE MODULE.............. 1591
U0141-LOST COMMUNICATION WITH TIP
MODULE................................. 1593
U1403-IMPLAUSIBLE FUEL LEVEL SIGNAL
RECEIVED............................... 1595U1412-IMPLAUSIBLE VEHICLE SPEED
SIGNAL RECEIVED....................... 1596
U0141-LOST COMMUNICATION WITH ECU . 1598
U1421-IMPLAUSIBLE IGNITION KEY OFF
TIME RECEIVED.......................... 1600

POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL)
1.POWERTRAIN VERIFICATION TEST VER - 4 (DIESEL)
1. Check if any of the following conditions exist.
2. The ECM has been disconnected or replace.
3. The Battery power has been disconnected.
4. Inspect the vehicle to ensure that all engine components are properly installed and connected. Reassemble and
reconnect components as necessary.
5. With the DRBIII
,eraseDTCs.
6. If the ECM has been replaced, perform steps 11 through 13, then continue with the verification.
7. If ECM has been changed and correct VIN and mileage have not been programmed, a DTC will be set in ABS
and Air bag modules. In addition, if vehicle is equipped with a Sentry Key Immobilizer Module (SKIM), Secret Key
data must be updated to enable start.
8. For ABS and Air Bag systems: Enter correct VIN and Mileage in ECM. Erase codes in ABS and Air Bag modules.
9. For SKIM theft alarm: Connect DRBIII
to data link conn. Go to Theft Alarm, SKIM, Misc. and place SKIM in
secured access mode, by using the appropriate PIN code for this vehicle. Select Update the Secret Key data. Data
will be transferred from SKIM to PCM
10. Turn the speed control ON (if equipped, cruise light will be on).
11. Depress and release the SET Switch. If the speed control did not engage,the repair is not complete. Check for
TSBs that pertain to speed control problem and then, if necessary, return to Symptom List.
12. Depress and hold the RESUME/ACCEL Switch. If the vehicle speed did not increase by at least 2 mph, the
repair is not complete. Check for TSBs that pertain to speed control problem and then, if necessary, return to Symp-
tom List.
13. Press and hold the COAST switch. The vehicle speed should decrease. If it did not decrease, the repair is not
complete. Check for TSBs that pertain to speed control problem and then, ifnecessary, return to Symptom List.
14. Using caution, depress and release the brake pedal. If the speed control did not disengage, the repair is not
complete. Check for TSBs that pertain to speed control problem and then, ifnecessary, return to Symptom List.
15. Bring the vehicle speed back up to 35 MPH.
16. Depress the RESUME/ACCEL switch. If the speed control did not resume the previously set speed, the repair
is not complete. Check for TSBs that pertain to speed control problem and then, if necessary, return to Symptom
List.
17. Hold down the SET switch. If the vehicle did not decelerate, the repair is not complete. Check for TSBs that
pertain to speed control problem and then, if necessary, return to SymptomList.
18. Ensure vehicle speed is greater than 35 mph and release the SET Switch. If vehicle did not adjust and set a
new vehicle speed, the repair is not complete. Check for TSBs that pertain to speed control problem and then, if
necessary, return to Symptom List.
19. Depress and release the CANCEL switch. If the speed control did not disengage, the repair is not complete.
Check for TSBs that pertain to speed control problem and then, if necessary, return to Symptom List.
20. Bring the vehicle speed back up above 35 mph and engage speed control.
21. Depress the OFF switch to turn OFF, (Cruise light will be off). If the speed control did not disengage, the repair
is not complete. Check for TSBs that pertain to speed control problem and then, if necessary, return to Symptom
List.
22. If the vehicle successfully passed all of the previous tests, the speedcontrol system is now functioning as
designed. The repair is now complete.
23. NOTE: OVERSHOOT/UNDERSHOOT FOLLOWING SPEED CONTROL SET.
24. If the vehicle operator repeatedly presses and releases the SET buttonwith their foot off of the accelerator
(referred to as
lift foot set), the vehicle may accelerate and exceed the desired set speed by up to 5 mph (8km/h).
25. It may also decelerate to less than the desired set speed, before finally achieving the desired set speed.
26. The Speed Control System has an adaptive strategy that compensates forvehicle-to-vehicle variations in speed
control cable lengths.
27. When the speed control is set with the vehicles operators foot off of theaccelerator pedal, the speed control
thinks there is excessive speed control cable slack and adapts accordingly.
28. If the
lift foot setsare continually used, a speed control overshoot/undershoot condition will develop.
29. To
unlearnthe overshoot/undershoot condition, the vehicle operator has to press and release the set button

P0477-LOW VOLTAGE ON THE ENGINE BRAKE DRIVER
For a complete wiring diagramRefer to Section 8W.
When Monitored:
When the ignition is on.
Set Condition:
When the signal from the engine brake driver output does not match the signal from the engine brake driver
feedback.
Possible Causes
WIRING HARNESS
ENGINE BRAKE DRIVER RELAY
FUSED B+ OPEN
ENGINE BRAKE DRIVER SIGNAL CIRCUIT OPEN
INTERMITTENT CONDITION
ENGINE BRAKE DRIVER SIGNAL CIRCUIT SHORTED TO BATTERY NEGATIVE
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.RELAY CLICKING
Turn the engine off (ignition on).
With the scan tool, actuate the exhaust brake relay.
Can you hear the Relay clicking?
Ye s>>
Go To 2
No>>
Go To 3
2.WIRING HARNESS
With the scan tool, actuate the exhaust brake relay.
While the relay is clicking, wiggle the wiring harness and connectors throughout the circuit.
Does this interrupt the clicking?
Ye s>>
Repair or replace the wiring harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 3
3.Engine Brake Driver Relay
Remove the Engine Brake Driver Relay.
Check connectors - Clean/repair as necessary.
Measure the resistance between terminals 86 and 85 of the engine brake relay.
Is the resistance less than 100 Ohms?
Ye s>>
Go To 4
No>>
Replace the Engine Brake Driver Relay.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)