2006 DODGE RAM SRT-10 sensor

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

7.S/C SIGNAL CIRCUIT SHORTED TO SENSOR GROUND
Measure the resistance between the S/C Signal Circuit and the Sensor
Ground Circuit at the ON/OFF switch harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Repair S/C Signal Circuit shorted to Sensor Ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Replace and program the ECM in accordance with the Ser-
vice Information.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

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

8.S/C SWITCH GROUND CIRCUIT OPEN CLOCKSPRING TO S/C SWITCH
Measure the resistance of the S/C Switch Sensor Ground Circuit
between the On/Off Switch 2-way harness connector to the clockspring
harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Repair open ground circuit from clockspring 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)
9.S/C SWITCH GROUND CIRCUIT OPEN ECM TO CLOCKSPRING
Measure the resistance of the S/C Switch Sensor Ground Circuit
between the ECM harness connector to the clockspring harness con-
nector.
Is the resistance below 5.0 ohms?
Ye s>>
Replace and program the ECM in accordance with the Ser-
vice Information.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Repair open ground circuit from 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)

P0642-LOW VOLTAGE AT THE #2 SENSOR SUPPLY CIRCUIT
For a complete wiring diagramRefer to Section 8W.

When Monitored:
With the key on.
Set Condition:
Voltage detected on the #2 sensor supply circuit is below a calibrated value.
Possible Causes
FAN CLUTCH ASSEMBLY
(K668) 5-VOLT SHORTED TO GROUND
(K668) 5-VOLT SUPPLY SHORTED TO ANOTHER CIRCUIT
FA N D T C
INTERMITTENT CONDITION
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.FAN CLUTCH ASSEMBLY
Disconnect the Fan clutch harness connector.
NOTE: Check connectors - Clean/repair as necessary.
With the scan tool, read DTCs.
Did P0483 set?
Ye s>>
Replace the Fan clutch assembly.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 2
2.(K668) 5-VOLT SHORTED TO GROUND
Turn the ignition off.
Disconnect the ECM harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the (K668) #2 5-volt supply (fan speed
sensor power) circuit in the sensor harness connector and battery neg-
ative.
Is the resistance greater than 100k Ohms?
Ye s>>
Go To 3
No>>
Repair the #2 (K668) 5-volt supply shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)

3.(K668) 5-VOLT SUPPLY SHORTED TO ANOTHER CIRCUIT
Measure the resistance between the sensor (K668) #2 5-volt supply
(fan speed sensor power) circuit in the ECM harness connector to all
other circuits in the ECM harness connectors
Is the resistance greater than 100k Ohms?
Ye s>>
Go To 4
No>>
Repair the 5-volt supply shorted to another circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
4.FA N D T C
Reconnect the ECM harness connectors.
Reconnect the disconnected Fan harness connector.
Turn the ignition on.
With the scan tool, read DTCs.
Is DTC P0483 set?
Ye s>>
Repair the Fan DTC.
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