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
INTERMITTENT CONDITION
For a complete wiring diagramRefer to Section 8W.
POSSIBLE CAUSES
INTERMITTENT CONDITION
Diagnostic Test
1.INTERMITTENT CONDITION
NOTE: The conditions that set the DTC are not present at this time. The following list may help in identi-
fying the intermittent condition.
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.
Refer to any Technical Service Bulletins (TSBs) that may apply.
Review the scan tool Freeze Frame information. If possible, try to duplicate the conditions under which the DTC set.
With the engine running at normal operating temperature, monitor the scantool parameters relatedtotheDTCwhile
wiggling the wire harness. Look for parameter values to change and/or a DTCto set.
Turn the ignition off.
Visually inspect the related wire harness. Disconnect all the related harness connectors. Look for any chafed,
pierced, pinched, partially broken wires and broken, bent, pushed out, orcorroded terminals.
Perform a voltage drop test on the related circuits between the suspected faulty component and the ECM.
Inspect and clean all ECM, engine, and chassis grounds that are related to the most current DTC.
If numerous trouble codes were set, use a wire schematic and look for any common ground or supply circuits.
For any Relay DTCs, actuate the Relay with the scan tool and wiggle the related wire harness to try to interrupt the
actuation.
For intermittent Evaporative Emission trouble codes perform a visual andphysical inspection of the related parts
including hoses and the Fuel Filler cap.
For intermittent Misfire DTC’s check for restrictions in the Intake and Exhaust system, proper installation of Sensors,
vacuum leaks, and binding components that are run by the accessory drive belt.
Use the scan tool to perform a System Test if one applies to failing component.
A co-pilot, data recorder, and/or lab scope should be used to help diagnoseintermittent conditions.
Were any problems found during the above inspections?
Ye s>>
Perform the necessary repairs.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No>>
Te s t C o m p l e t e .
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)
4.FUSED B+ OPEN
Ignition on, engine not running.
Measure the voltage of the Fused B+ Supply circuit at the Engine Brake Relay.
Is the voltage within 10% of battery voltage?
Ye s>>
Go To 5
No>>
Repair the open B+ circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
5.ENGINE BRAKE DRIVER SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the resistance of the Engine Brake Driver signal circuit between the Relay harness connector and the ECM
harness connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 6
No>>
Repair the open Engine Brake driver circuit open from relay to ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
6.ENGINE BRAKE DRIVER SIGNAL CIRCUIT SHORTED TO BATTERY NEGATIVE
Measure the resistance of the Engine Brake Driver signal circuit between the Relay connector and battery negative.
Is the resistance greater than 100k Ohms?
Ye s>>
Go To 7
No>>
Repair Engine brake driver shorted to Battery negative.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
7.ECM
Reconnect the ECM harness connectors.
Using the scan tool, actuate the Engine Brake Driver Relay.
While monitoring with the scan tool, use a jumper wire to connect 12 volts tothe relay signal circuit with the relay
disconnected.
Did the DTC P0478?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
No>>
Replace ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
P0478-HIGH 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
RELAY LOOSE
ENGINE BRAKE DRIVER CONTROL CIRCUIT SHORTED TO VOLTAGE
ENGINE BRAKE RELAY
INTERMITTENT CONDITION
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.RELAY
Ignition on, engine not running.
With the scan tool, actuate the Engine Brake Driver Relay.
Can you hear the Relay clicking?
Ye s>>
Go To 2
No>>
Go To 3
2.RELAY LOOSE
While the relay is clicking, wiggle the wiring harness and connectors.
Does this interrupt the clicking?
Ye s>>
Repair the loose connection.
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 Control Circuit
Turn the ignition off.
Remove the Engine Brake Driver Relay.
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the voltage of the Engine Brake Driver Control Circuit between therelay terminal and battery negative.
Is the voltage less than 1 volt?
Ye s>>
Go To 4
No>>
Repair Engine Brake Driver Control Circuit shorted to voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
4.Engine brake relay
Measure the resistance between terminals 85 and 86 of the engine brake relay.
Is the resistance less than 10 ohms?
Ye s>>
Replace the engine brake relay.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 5
5.ECM
Reconnect the ECM harness connectors.
Reinstall the Engine Brake relay.
Ignition on, engine not running.
While monitoring with the scan tool, remove the Engine Brake Driver Relay.
Did P0477 set?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
No>>
Replace the ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
P0541-LOW VOLTAGE ON THE #1 INTAKE AIR HEATER RELAY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
When the ignition is on.
Set Condition:
When the signal from the #1 intake air heater output does not match the signal from the #1 intake air heater
feedback.
Possible Causes
LOOSE CONNECTION
INTAKEAIRHEATERRELAY
SIGNAL CIRCUIT OPEN FROM RELAY TO ECM
SIGNAL CIRCUIT SHORTED TO BATTERY NEGATIVE
ECM
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.RELAY CLICKING
Ignition on, engine not running.
With the scan tool, actuate the #1 Intake Air Heater.
Can you hear the Relay clicking?
Ye s>>
Go To 2
No>>
Go To 3
2.LOOSE CONNECTION
While the relay is clicking , wiggle the wiring harness and connectors.
Does this interrupt the clicking?
Ye s>>
Repair the poor connection.
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.INTAKE AIR HEATER RELAY
Turn the ignition off.
Remove the Intake Air Heater #1 Relay.
Check connectors - Clean/repair as necessary.
Measure the resistance between the signal and return posts of the intake air heater relay.
Is the resistance between 15 and 25 Ohms?
Ye s>>
Go To 4
No>>
Replace the Intake Air Heater #1 relay.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)