Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
B7 CHECK THE ISP-R VOLTAGE AT THE PCM
• PCM Power Relay connector connected.
• Ignition ON, engine OFF.
• Measure the voltage between:
( + ) PCM Connector, Harness Side | ( - ) |
|---|---|
ISP-R | Ground |
Is the voltage greater than 10.5 V?
Yes | No |
|---|---|
For DTCs P0689 and P2510, GO to B13 . For all others, GO to B8 . | REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. |
B8 CHECK FOR AN OPEN VPWR CIRCUIT BETWEEN THE PCM AND POWER RELAY
• Ignition OFF.
• PCM connector disconnected.
• Measure the resistance between:
( + ) PCM Power Relay Connector, Harness Side | ( - ) PCM Connector, Harness Side |
|---|---|
VPWR | VPWR |
Is the resistance less than 5 ohms?
Yes | No |
|---|---|
For DTC P068A, GO to B13 . For all others, INSTALL a new PCM Power relay. Clear the PCM DTCs. REPEAT the self-test. | REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. |
B9 CHECK THE PCMRC CIRCUIT FOR A SHORT TO GROUND
• Ignition OFF.
• PCM Power Relay connector disconnected.
• PCM connector disconnected.
• Measure the resistance between:
( + ) PCM Connector, Harness Side | ( - ) |
|---|---|
PCMRC | Ground |
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.