Pinpoint Test M: 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 DTCs. Check for other DTCs 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 DTCs 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

M1 CHECK FOR DTCS

NOTE: 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 DTCs from the PCM.
Are DTCs P0685, P068A or P06B8 present?

Yes For DTCs P068A or P06B8, GO to M2. For DTC P0685, GO to M7.

No GO to M3

M2 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 M3

No REPAIR as necessary. REFER to: Charging System - 3.5L Duratec (202kW/275PS)
Clear the PCM DTCs. REPEAT the self-test.

M3 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-33 Harness side	Courtesy of FORD MOTOR COMPANY	C1551B-60 Harness side

Is the resistance less than 3 Ohm?

Yes

GO to M4

No	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

M4 CHECK THE PCMRC CIRCUIT FOR A SHORT TO VOLTAGE

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1551B-60 Harness side	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

GO to M5

M5 CHECK THE ISP-R VOLTAGE AT THE PCM

Ignition OFF.

Disconnect PCM electrical connector.

Connect BJB electrical connector C1035A.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1551B-13 Harness side	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 10.5 V?

Yes

GO to M6

No	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

M6 CHECK FOR AN OPEN VPWR CIRCUIT

Ignition OFF.

Disconnect BJB electrical connector C1035A.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1035A-42 Harness side	Courtesy of FORD MOTOR COMPANY	C1551B-1 Harness side
C1035A-42 Harness side	Courtesy of FORD MOTOR COMPANY	C1551B-2 Harness side
C1035A-42 Harness side	Courtesy of FORD MOTOR COMPANY	C1551B-16 Harness side

Are the resistances less than 3 ohm?

Yes	For DTC P068A, GO to M9. INSTALL a new BJB. Clear the PCM DTCs. REPEAT the self-test.

No	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

M7 CHECK THE PCMRC CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Disconnect PCM electrical connector C1551B.

Disconnect BJB electrical connector C1035A.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1551B-60 Harness side	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10 kOhm?

Yes

GO to M8

No	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

M8 CHECK THE ISP-R CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1551B-13 Harness side	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

GO to M9

M9 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 Engine Controls - Diagnostic Methods (Except Diesel & Hybrid) , Flash Electrically Erasable Programmable Read Only Memory (EEPROM), 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.