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.
4-66 Powertrain DTC Charts and Descriptions
Diagnostic Trouble Code (DTC) Charts and Descriptions
P0391 - Camshaft Position Sensor B Circuit Range/Performance (Bank 2) (Continued) Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test DR.
P0394 - Camshaft Position Sensor B Circuit Intermittent (Bank 2)
Description: This DTC sets when the CMP21 (6.2L) or CMP22 (all others) circuit signal is intermittent. For additional
camshaft position (CMP) sensor location information, refer to Section 1, Engine Control Components.
Possible Causes: • Intermittent open circuit
• Intermittent short circuit
• Camshaft timing incorrectly set
• Camshaft position sensor trigger wheel out of alignment
• Damaged camshaft position bank 2 sensor 1 (CMP21) shielding (6.2L)
• Damaged camshaft position bank 2 sensor 2 (CMP22) shielding (all others)
• Incorrect harness connections
• Corrosion
• Damaged CMP21 sensor (6.2L)
• Damaged CMP22 sensor (all others)
Diagnostic Aids: Harness routing, harness alterations, incorrect shielding, or electrical interference from other systems may have
an intermittent impact on the CMP signal.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test DR.
P0400 - Exhaust Gas Recirculation (EGR) Flow
Description: The electric EGR (EEGR) system is monitored once per drive cycle at high and low load conditions. This DTC
sets when a concern is detected by PCM calculations indicating the EGR flow is less or greater than expected.
Possible Causes: • EEGR valve stuck open or closed
• EEGR connector not seated correctly
• EEGR stepper motor
• VPWR circuit open
• EGRMC circuit open
• EGRMC circuit short to voltage
• EGRMC circuit short to ground
• Vacuum signal to manifold absolute pressure (MAP) sensor restricted or leaking
• Mass airflow (MAF) sensor signal erroneous
• Carbon build up in the EEGR valve seat area
Diagnostic Aids: The following sensors input data to the PCM for correct operation of the EEGR system: engine coolant
temperature (ECT), crankshaft position (CKP), intake air temperature (IAT), MAF, throttle position (TP), MAP and vehicle speed sensor (VSS). Diagnose any DTC relating to these sensors prior to addressing this DTC.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test KD.
P0403 - Exhaust Gas Recirculation (EGR) Control Circuit
Description: The electric EGR (EEGR) system is continuously monitored to check the four EEGR motor coils, circuits, and
the PCM for opens, shorts to voltage and ground. If a concern is detected, the EEGR system is disabled and additional monitoring is suspended for the remainder of the drive until the next drive cycle.
Possible Causes: • EEGR stepper motor windings open
• EEGR connector not seated correctly
• EGRMC circuit open
• EGRMC circuit short to voltage
• EGRMC circuit short to ground
• Damaged PCM
Diagnostic Aids:
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test KD.
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.