G2 CHECK THE COMMUNICATION NETWORK
Do the FCIM and the PCM pass the network test?
Yes | GO to G3 | |
|---|---|---|
No | DIAGNOSE the FCIM or PCM does not communicate with the diagnostic scan tool. REFER to: Communications Network (418-00 Module Communications Network, Diagnosis and Testing). | |
G3 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) PRESSURE SENSOR (ACP_PRESS) PID (PARAMETER IDENTIFICATION)
Ignition ON. Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs). With a manifold gauge set connected, compare the pressure readings of the manifold gauge set and the PCM ACP_PRESS PID.
Are the pressure values of the manifold gauge set and the ACP_PRESS PCM PID within ± 103 kPa (15 psi)?
Yes | GO to G4 | |
|---|---|---|
No | DIAGNOSE the A/C pressure transducer. GO to Pinpoint Test A | |
G4 ELECTRIC COOLING FAN FUNCTIONAL CHECK
Ignition ON. Using a diagnostic scan tool, carry out the PCM KOEO self-test.
Does the electric cooling fan operate sometime during the KOEO self-test?
Yes | GO to G5 | |
|---|---|---|
No | DIAGNOSE the electric cooling fan operation. REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual, Section 3 Symptom Charts. | |
G5 COMPARE THE PCM (POWERTRAIN CONTROL MODULE) INTAKE AIR TEMPERATURE (IAT) PID (PARAMETER IDENTIFICATION) AND THE OTHER TEMPERATURE SENSOR READINGS TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PID (PARAMETER IDENTIFICATION)
NOTE: Compare multiple engine sensor readings to the ambient temperature to determine sensors are reading correctly. A faulty sensor can cause the PCM to disable the A/C with or without a DTC.
Allow the vehicle exterior and interior to stabilize to ambient temperature. This can take a soak period of at least 6 hours. Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs). Monitor the CHT, ECT, IAT, MAPT, and AAT Parameter Identifications (PIDs) (as applicable).
Are the temperature values similar (typically within 18ºC (32.4ºF)?
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.