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.
Powertrain DTC Charts and Descriptions 4-75
Diagnostic Trouble Code (DTC) Charts and Descriptions
P0505 - Idle Air Control (IAC) System (Continued)
• Damaged PCM
Diagnostic Aids: This DTC may be accompanied by other DTCs. Diagnose other DTCs first. If no other DTCs are present,
inspect the intake air system for air restrictions, vacuum leaks, and damage. If no concerns are present, clear the DTC and carry out the KOER, self-test.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test HU.
P0506 - Idle Air Control (IAC) System RPM Lower Than Expected
Description: This DTC sets when the engine idle speed is less than the desired RPM.
Possible Causes: • Intake air restriction
• Vacuum leaks
• Exhaust restriction
• Engine mechanical concern
• Sludged throttle body
• Damaged electronic throttle body (ETB)
• Damaged PCM
Diagnostic Aids: This DTC may be accompanied by other DTCs. Diagnose other DTCs first. If no other DTCs are present,
inspect the intake air system for air restrictions, vacuum leaks, and damage. If no concerns are present, clear the DTC and carry out the key ON, engine running (KOER), self-test.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test HU.
P0507 - Idle Air Control (IAC) System RPM Higher Than Expected
Description: This DTC sets when the engine idle speed is greater than the desired RPM.
Possible Causes: • Intake air leak after throttle body
• Vacuum leaks
• Damaged evaporative emission (EVAP) system
• Exhaust gas recirculation (EGR) valve leaks vacuum
• Damaged electronic throttle body (ETB)
• Damaged PCM
Diagnostic Aids: This DTC is informational only and it may be accompanied by other DTCs. Diagnose other DTCs first. If no
other DTCs are present, inspect the intake air system for air restrictions, vacuum leaks, and damage. If no concerns are present, clear the DTC and repeat the self-test.
Application Key On Engine Off Key On Engine Running Continuous Memory
All Refer to the Description, Possible Causes and Diagnostic Aids for the DTC.
P050A - Cold Start Idle Air Control Performance
Description: This DTC sets when the difference between desired and actual engine speed exceeds the calibrated threshold.
Possible Causes: • Intake air restriction
• Exhaust restriction
• Engine mechanical concern
• Damaged or sludged electronic throttle body (ETB)
• Vacuum leaks
• Damaged PCM
Diagnostic Aids: Disregard the freeze frame data. Freeze frame data does not apply to the cold start monitor.
This DTC is informational only and may be accompanied by other DTCs. Diagnose other DTCs first. If no other DTCs are present, inspect the intake air system for air restrictions, vacuum leaks, and damage. If no concerns are present, clear the DTCs and verify the engine coolant temperature is below 37.8°C (100°F). Allow the vehicle to soak for 2 to 3 hours if necessary for the engine coolant temperature to fall below 37.8°C (100°F). Start the engine without touching the accelerator pedal and allow the engine to idle for 6 minutes in park. If no DTCs are present and the malfunction indicator lamp (MIL) is not illuminated after idling for 6 minutes, carry out the key ON, engine running (KOER), self-test to confirm that no DTCs are present and the repair is complete.
Application Key On Engine Off Key On Engine Running Continuous Memory
2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015
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.