P2121

[MMeier]

Pedal position sensor 1 performance/ rationality..... can someone translate this to english for me please???? TIA! again !

 

[Bob4x4]

Sent you an email it was too big to post.



Bob

 

[MMeier]

Thanks Bob, pretty comprehensive test procedure. Hate to do this, anything on my P0647?

 

[Bob4x4]

P0647-HIGH VOLTAGE DETECTED AT THE A/C CLUTCH RELAY









For a complete wiring diagram Refer to Section 8W.



When Monitored:

When the ignition is on.



Set Condition:

When the signal from the A/C Clutch output does not match the signal from the A/C Clutch feedback.



Possible Causes

LOOSE CONNECTION

SHORTED TO EXTERNAL VOLTAGE

FUSED BATTERY SUPPLY

A/C CLUTCH RELAY

INTERMITTENT CONDITION

ECM





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. CLUTCH CLICKING



--------------------------------------------------------------------------------

Ignition on, engine not running.

With the scan tool, actuate the A/C clutch relay.



Can you hear the Relay clicking?



Yes

Go To 2



No

Go To 3







2. LOOSE CONNECTION



--------------------------------------------------------------------------------

Actuation still running.

While the relay is clicking, wiggle the wiring harness and connectors throughout the circuit.



Does this interrupt the clicking?



Yes

Repair the loose connection.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



No

Go To 3







3. FUSED BATTERY SUPPLY



--------------------------------------------------------------------------------

Ignition off.

Disconnect the ECM connectors.

Remove the A/C clutch relay.



NOTE: Check connectors - Clean/repair as necessary.





Ignition on, engine not running.

Measure the voltage on the Fused Battery Supply circuit between the PDC and battery negative.



Is the voltage less than 1 volt?



Yes

Go To 4



No

Repair the short to voltage.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)







4. A/C CLUTCH RELAY



--------------------------------------------------------------------------------







Remove the A/C Clutch Relay from the PDC.



NOTE: Check connectors - Clean/repair as necessary.





Measure the resistance between terminals 85 and 86 of the A/C Clutch Relay.



Is the resistance less than 10 Ohms?



Yes

Go To 5



No

Replace the A/C clutch relay.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)







5. ECM



--------------------------------------------------------------------------------

Reconnect the ECM harness connectors.

Reinstall the A/C clutch relay.

With the scan tool, actuate the A/C clutch relay.

Turn the ignition on.

While monitoring with the scan tool, disconnect the A/C Clutch Relay from the PDC.



Did DTC P0646 set?



Yes

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/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

 

[MMeier]

Thanks a bunch, now to find a scan tool! What are ECM's going for nowadays?

 

[Bob4x4]

Retail about1. 5k they come w/out software We choose and install the correct version.



Bob

 

[MMeier]

Retail about1. 5k they come w/out software We choose and install the correct version.



Bob

Lets see what happens here, cleared the codes this afternoon at the meet and the only one thats come back is the A/C related one. I'm kinda leaning toward the clutch itself is up to no good. With 176 k on the original I might just go and spring for a new compressor with clutch. The way this things been lately, I'll put a clutch on it and the damn compressor will lock up next week !! #@$%! Bob, how much for a WHOLESALE used good ECM???