Pinpoint Test L: Powertrain Control Module (Pcm) Power Relay
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- Normal Operation and Fault Conditions
Refer to the DTC Fault Trigger Conditions.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P0685:00 ECM/PCM Power Relay Control Circuit/Open: No Sub Type Information Sets when the ISP-R circuit indicates the ignition is in the OFF, ACC, or LOCK mode, and the amount of time the PCM remains powered through the PCM power relay exceeds a predetermined amount of time. Ability to communicate with the PCM when the ignition is in the OFF, ACC, or LOCK mode indicates a hard fault. PCM P068A:00 ECM/PCM Power Relay De-Energized - Too Early: No Sub Type Information Sets when the non volatile random access memory write did not complete successfully after the ignition key was turned OFF, prior to PCM shutdown. This DTC also sets when the PCM power relay is de-energized too early. PCM P06B8:00 Internal Control Module Non-Volatile Random Access Memory (NVRAM) Error: No Sub Type Information Sets when the PCM detects a concern with the ability of the PCM to correctly store permanent DTC s. Check for other DTC s and diagnose those first. Check for aftermarket performance products. Check for an electrical or charging system concern. If an updated calibration is available, update the calibration to the latest level. If an updated calibration is not available, clear the DTC s and repeat the self-test. If this DTC is retrieved after a PCM reprogramming, turn the ignition OFF and allow the PCM to complete a normal power down sequence. Possible Sources
- PCM power circuitry concern
- PCM power relay
- PCM
- L1 CHECK FOR DTCSNOTE: If DTC P068A or P06B8 is retrieved after a PCM reprogramming, turn the ignition OFF and allow the PCM to complete a normal power down sequence. Clear the PCM DTCs and repeat the PCM self-test. If DTC P068A or P06B8 is retrieved again, continue with this pinpoint test.
- Using a diagnostic scan tool, retrieve all DTC s from the PCM.
Are DTC s P0685, P068A or P06B8 present?
Yes For DTC s P068A or P06B8, GO to L2. For DTC P0685, GO to L7. No GO to L3 - L2 CHECK THE BATTERY AND CHARGING SYSTEM
- Check the battery and charging system voltages. REFER to: Charging System - 3.5L Duratec (202kW/275PS)
Are the battery and charging system voltages within specification?
Yes GO to L3 No REPAIR as necessary. REFER to: Charging System - 3.5L Duratec (202kW/275PS)
. Clear the PCMDTC s. REPEAT the self-test. - L3 CHECK THE PCMRC CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect PCM electrical connector.
- Disconnect BJB electrical connector C1035A.
- Measure:
Positive Lead Measurement / Action Negative Lead C1035A Pin 33 Harness side C1551B Pin 60 Harness side
Is the resistance less than 3 Ohm?
Yes GO to L4 No REPAIR the open circuit. Clear the PCMDTC s. REPEAT the self-test. - L4 CHECK THE PCMRC CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
Is any voltage present?
Yes REPAIR the short circuit. Clear the PCMDTC s. REPEAT the self-test. No GO to L5 - L5 CHECK THE ISP-R VOLTAGE AT THE PCM
- Ignition OFF.
- Disconnect PCM electrical connector.
- Connect BJB electrical connector C1035A.
- Ignition ON.
Is the voltage greater than 10.5 V?
Yes GO to L6 No REPAIR the open circuit. Clear the PCMDTC s. REPEAT the self-test. - L6 CHECK FOR AN OPEN VPWR CIRCUIT
- Ignition OFF.
- Disconnect BJB electrical connector C1035A.
- Measure:
Positive Lead Measurement / Action Negative Lead C1035A Pin 42 Harness side C1551B Pin 1 Harness side C1035A Pin 42 Harness side C1551B Pin 2 Harness side C1035A Pin 42 Harness side C1551B Pin 16 Harness side
Are the resistances less than 3 ohm?
Yes For DTC P068A, GO to L9. INSTALL a new BJB. Clear the PCMDTC s. REPEAT the self-test. No REPAIR the open circuit. Clear the PCMDTC s. REPEAT the self-test. - L7 CHECK THE PCMRC CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect PCM electrical connector C1551B.
- Disconnect BJB electrical connector C1035A.
Is the resistance greater than 10 kOhm?
Yes GO to L8 No REPAIR the short circuit. Clear the PCMDTC s. REPEAT the self-test. - L8 CHECK THE ISP-R CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
Is any voltage present?
Yes REPAIR the short circuit. Clear the PCMDTC s. REPEAT the self-test. No GO to L9 - L9 CHECK FOR CORRECT PCM OPERATION
- Ignition OFF.
- Disconnect All the PCM electrical connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect All the PCM electrical connectors and make sure they seat correctly.
- Carry out the PCM self-test.
Is the concern still present?
Yes INSTALL a new PCM. REFER to Reprogram or update the PCM calibration. Refer to PROGRAMMING THE VID BLOCK FOR A REPLACEMENT PCM . No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.