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.
B4 CHECK THE B+ VOLTAGE TO PCM POWER RELAY
• PCM Power Relay connector disconnected.
• Ignition ON, engine OFF.
• Measure the voltage between:
( + ) PCM Power Relay Connector, Harness Side | ( - ) |
|---|---|
B+ | Ground |
Is the voltage greater than 10.5 V?
Yes | No |
|---|---|
GO to B5 . | REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. |
B5 CHECK THE PCMRC CIRCUIT FOR AN OPEN
• Ignition OFF.
• PCM connector disconnected.
• Measure the resistance between:
( + ) PCM Power Relay Connector, Harness Side | ( - ) PCM Connector, Harness Side |
|---|---|
PCMRC | PCMRC |
Is the resistance less than 5 ohms?
Yes | No |
|---|---|
GO to B6 . | REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. |
B6 CHECK THE PCMRC CIRCUIT FOR A SHORT TO VOLTAGE
• Ignition ON, engine OFF.
• Measure the voltage between:
( + ) PCM Connector, Harness Side | ( - ) |
|---|---|
PCMRC | Ground |
Is any voltage present?
Yes | No |
|---|---|
REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. | GO to B7 . |
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.