2006 DODGE RAM SRT-10 check engine

When Monitored:
While the ignition is on
Set Condition:
Speed control MUX switch below 1.0 volts for 5 seconds.
Possible Causes
S/C WIRING HARNESS OBSERVABLE PROBLEM
S/C SWITCH (ON/OFF)
CLOCKSPRING SHORTED TO GROUND
S/C SWITCH (RESUME/ACCEL)
S/C SWITCH SIGNAL CIRCUIT SHORTED TO GROUND
S/C SIGNAL CIRCUIT SHORTED TO SENSOR GROUND
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.S/C SWITCH VOLTAGE BELOW 1.0 VOLT
Turn the ignition on.
With the scan tool, read the S/C Switch volts status in the ECM.
Is the S/C Switch voltage below 1.0 volt?
Ye s>>
Go To 3
No>>
Go To 2
2.S/C WIRING HARNESS OBSERVABLE PROBLEM
Turn the ignition off.
Using the Schematics as a guide, inspect the Wiring and Connectors.
Were any problems found?
Ye s>>
Repair as necessary.
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.S/C SWITCH (ON/OFF)
Turn the ignition off.
Disconnect the S/C ON/OFF Switch harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Turn the ignition on.
With the scan tool in Sensors, read the S/C Switch volts in the ECM.
Did the S/C Switch volts change to 5.0 volts?
Ye s>>
Replace the S/C ON/OFF Switch.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 4

4.S/C SWITCH (RESUME/ACCEL)
Turn the ignition off.
Disconnect the S/C RESUME/ACCEL Switch harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
With the scan tool in Sensors, read the S/C Switch volts in the ECM.
Did the S/C Switch volts go above 4.0 volts?
Ye s>>
Replace the Resume/Accel Switch.
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.CLOCKSPRING SHORTED TO GROUND
Turn the ignition off.
Disconnect the clockspring6-way harness connector (instrument panel
wiring side).
Turn the ignition on.
With the scan tool in Sensors, read the S/C Switch volts in the ECM.
Did the S/C Switch volts change to 5.0 volts?
Ye s>>
Replace the Clockspring.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 6
6.S/C SWITCH SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the S/C ON/OFF Switch harness connector.
Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the S/C Switch Signal circuit and
ground (B-) at S/C ON/OFF Switch harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Repair S/C Switch Signal Circuit for a short to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 7

3.CLOCKSPRING SIGNAL/GROUND CIRCUIT OPEN
Disconnect the upper and lower clockspring harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the sensor ground circuit between the upper
and lower clockspring harness connectors.
Measure the resistance of the speed control switch signal circuit
between the upper and lower clockspring harness connectors.
Was the resistance above 5.0 ohms for either circuit?
Ye s>>
Replace the clockspring.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 4
4.SPEED CONTROL ON/OFF SWITCH
Disconnect the Speed Control On/Off Switch 2-way harness connector only.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance across the S/C On/Off Switch.
Is the resistance between 20.3K and 20.7K ohms?
Ye s>>
Go To 5
No>>
Replace the On/Off Switch.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
5.S/C SWITCH SIGNAL CKT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the S/C Switch Signal Circuit at the On/Off
Switch 2-way connector.
Is the voltage above 6.0 volts?
Ye s>>
Repair the Speed Control Switch Signal Circuit for a short
to voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 6

6.S/C SWITCH SIGNAL CIRCUIT OPEN ECM TO CLOCK SPRING
Turn the ignition off.
Disconnect the ECM harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the S/C Switch Signal Circuit between the
ECM connector and the Clockspring Connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 7
No>>
Repair open Speed Control Switch Signal Circuit ECM to
Clockspring.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
7.S/C SWITCH SIGNAL CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
Measure the resistance of the S/C Switch Signal Circuit from the clock-
spring harness connector to the On/Off switch harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 8
No>>
Repair the open Speed Control Switch Signal Circuit Clock-
spring to S/C switch.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

P0602-CHECKSUM ERROR
For a complete wiring diagramRefer to Section 8W.
When Monitored:
While the ignition is on.
Set Condition:
A deviation between the ECM memory and a stored calibration.
Possible Causes
FLASH ECM
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.FLASH ECM
Using the scan tool, reflash the ECM with the proper calibration for the particular truck.
Is the flash successful?
Ye s>>
Repair complete.
No>>
Go To 2
2.ECM
With the scan tool, read DTCs.
Did P0602 set after the reflash?
Ye s>>
Replace the ECM.
No>>
Te s t C o m p l e t e .
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

When Monitored:
When the ignition is on.
Set Condition:
The feedback signal does not match the commanded signal for the voltage regulator.
Possible Causes
GENERATOR
OPEN DRIVER CIRCUIT
GEN SOURCE SHORTED TO BATTERY NEGATIVE
(K20) FIELD DRIVER CIRCUIT SHORTED TO VOLTAGE
GEN SOURCE OPEN
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.GENERATOR
Turn the ignition off.
Disconnect the Generator field harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance between the generator field terminals.
Is the resistance between .5 and 15 Ohms?
Ye s>>
Go To 2
No>>
Replace the Generator.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

2.OPEN DRIVER CIRCUIT
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the resistance of the generator driver wire between the gener-
ator harness connector and the ECM harness connector.
Is the resistance less than 10 ohms.
Ye s>>
Go To 3
No>>
Repair the open driver circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
3.GENERATOR FIELD CIRCUIT OPEN
Measure the resistance of the generator field return circuit between the
generator harness connector and battery negative.
Is the resistance less than 10 ohms.
No>>
Repair the Generator field return shorted to Battery nega-
tive.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Ye s>>
Go To 4

When Monitored:
Whilethekeyison.
Set Condition:
The commanded signal to the fuel lift pump circuit in the TIPM does not matchthe feedback signal from the
fuel lift pump circuit.
Possible Causes
WIRING HARNESS
TIPM
FUEL LIFT PUMP CONTROL CIRCUIT SHORTED TO EXTERNAL VOLTAGE
FUEL LIFT PUMP CONTROL CIRCUIT OPEN
FUEL LIFT PUMP GROUND CIRCUIT OPEN
FUEL LIFT PUMP GROUND CIRCUIT SHORTED TO EXTERNAL VOLTAGE
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.POWER AT TPIM
Using a voltmeter, measure the voltage on the Battery Supply wire to the TIPM.
Turn the ignition on, engine off.
Does the voltmeter show battery voltage?
No>>
Fix or replace the open circuit in the Battery Supply Circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
Ye s>>
Go To 2
2.DAMANGED WIRING HARNESS
Turn Ignition off.
Disconnect the ECM and TIPM connectors. Inspect the connectors for signs of damage or corrosion.
NOTE: Check connectors - Clean/repair as necessary.
Are any pins damaged?
Ye s>>
Fix or replace the 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 5
3.FUEL LIFT PUMP CONTROL CIRCUIT OPEN
Using an ohmmeter, measure the resistance of the lift pump control circuitbetween the ECM connector and the
TIPM connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 4
No>>
Repair the open ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)