2006 DODGE RAM SRT-10 ignition

When Monitored:
While the ignition is on.
Set Condition:
The brake switch status is = to ON and the not brake switch status is = to OFF for a calibrated amount of time.
Possible Causes
DAMAGED WIRING HARNESS OR CONNECTORS
BRAKE SWITCH CIRCUIT OPEN (BRAKE SWITCH WILL ALWAYS BE ON)
BRAKE SWITCH CIRCUIT SHORTED TO BATTERY VOLTAGE (BRAKE SWITCH WILL ALWAYSBE ON)
BRAKE SWITCH
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.BRAKE SWITCH CIRCUIT OPEN
Turn the ignition off.
Disconnect the brake switch connection. Inspect the pins and connector
for damage, corrosion, etc.
Disconnect the ECM connectors. Inspect the pins and connector for
damage, corrosion, etc.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the brake switch signal circuits in the
ECM connector and the brake switch connector.
Is the resistance less than 10 ohms?
Ye s>>
Go To 2
No>>
Repair the open brake switch circuits.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

2.BRAKE SWITCH CIRCUIT SHORTED TO VOLTAGE
Measure the voltage between the brake switch circuits in the ECM con-
nector and battery negative.
Is the voltage less than 1 volt?
Ye s>>
Go To 3
No>>
Repair the open circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
3.ECM
Reconnect the ECM connectors.
Install a jumper wire in the brake switch connector between signal circuitand to ground.
Turn the ignition on.
Cycle the brake pedal several times.
Using the scan tool, read the DTC’s.
Is the DTC for brake switch low voltage present?
Ye s>>
Go To 4
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)
4.BRAKE SWITCH
Reconnect the brake switch connector.
Using the scan tool, clear the DTC’s.
Turn the ignition on.
Cycle the brake pedal several times.
Using the scan tool, read the DTC’s.
Has the brake switch High DTC returned?
Ye s>>
Replace the brake switch.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Perform Intermittent condition test. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

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

When Monitored:
Key on or Engine running.
Set Condition:
Speed Control MUX switch above 11.5 volts for 5 seconds.
Possible Causes
S/C WIRING HARNESS OBSERVABLE PROBLEM
CLOCKSPRING SIGNAL/GROUND CIRCUIT OPEN
SPEED CONTROL ON/OFF SWITCH
S/C SWITCH SIGNAL CKT SHORTED TO VOLTAGE
S/C SWITCH SIGNAL CIRCUIT OPEN ECM TO CLOCK SPRING
S/C SWITCH SIGNAL CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
S/C SWITCH GROUND CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
S/C SWITCH GROUND CIRCUIT OPEN ECM TO CLOCKSPRING
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.Scan tool SHOWS SPEED CONTROL SWITCH ON/OFF
Turn the ignition on.
With the scan tool in Inputs/Outputs, read the Speed Control inputs state inECM.
While monitoring the scan tool, push the Speed Control On/Off Switch several times, then leave it on.
Did the scan tool show Speed Control Switch off and on?
Ye s>>
Go To 2
No>>
Te s t C o m p l e t e .
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.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)