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.
4-88 Powertrain DTC Charts and Descriptions
Diagnostic Trouble Code (DTC) Charts and Descriptions
P064D - Internal Control Module O2 Sensor Processor Performance - Bank 1 (Continued)
• Damaged PCM
Diagnostic Aids: Check for other DTCs and diagnose those first. Check for intermittent universal HO2S wiring concerns. Check
the universal HO2S wiring between the PCM and the sensor for damage. Check for aftermarket performance products. Reprogram or update the calibration. Clear the DTCs, repeat the self-test. If the DTC is retrieved again, install a new PCM. Refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM).
Application Key On Engine Off Key On Engine Running Continuous Memory
All Refer to the Description, Possible Causes and Diagnostic Aids for the DTC.
P064E - Internal Control Module O2 Sensor Processor Performance - Bank 2
Description: The PCM monitors the application specific integrated circuit that controls and monitors the universal heated
oxygen sensor bank 2, sensor 1 (HO2S21). This DTC sets when the PCM detects an internal circuit or communication concern.
Possible Causes: • Damaged universal HO2S21 wiring
• Damaged PCM
Diagnostic Aids: Check for other DTCs and diagnose those first. Check for intermittent universal HO2S wiring concerns. Check
the universal HO2S wiring between the PCM and the sensor for damage. Check for aftermarket performance products. Reprogram or update the calibration. Clear the DTCs, repeat the self-test. If the DTC is retrieved again, install a new PCM. Refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM).
Application Key On Engine Off Key On Engine Running Continuous Memory
All Refer to the Description, Possible Causes and Diagnostic Aids for the DTC.
P0652 - Sensor Reference Voltage B Circuit Low
Description: This DTC sets when the electronic throttle control reference voltage (ETCREF) circuit is less than VREF
minimum.
Possible Causes: • ETCREF circuit short to ground
• Damaged sensor
• Incorrect harness connection
Diagnostic Aids: This DTC sets due to an under voltage condition on the ETCREF circuit.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test C.
P0653 - Sensor Reference Voltage B Circuit High
Description: This DTC sets when the electronic throttle control reference voltage (ETCREF) circuit is greater than VREF
maximum.
Possible Causes: • ETCREF circuit short to voltage
• Damaged sensor
• Incorrect harness connection
Diagnostic Aids: This DTC sets due to an over voltage condition on the ETCREF circuit.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test C.
P0657 - Actuator Supply Voltage A Circuit/Open
Description:
Possible Causes:
Diagnostic Aids: Refer to the Workshop Manual Section 303-14, Electronic Engine Controls.
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.