Condition | Possible Sources | Actions |
|---|---|---|
The differential oil pump never runs | Fuse Wiring, terminals or connectors Temperature sensor Differential oil pump relay Differential oil pump PCM | GO to Pinpoint Test D |
The differential oil pump runs continuously | Fuse Wiring, terminals or connectors Temperature sensor Differential oil pump relay PCM | GO to Pinpoint Test D |
Pinpoint Tests
DTC P1888
Refer to Wiring Diagrams Cell 25 for schematic and connector information.
Normal Operation and Fault Conditions
The temperature sensor is hardwired to the PCM. The PCM utilizes a fixed resistor (pull-up resistor) in series with the temperature sensor to monitor the entire temperature sensor circuit. As the differential oil temperature changes, the resistance in the temperature sensor changes which causes a variation in total circuit current flow resulting in a varying voltage drop across the pull-up resistor. The voltage signal used by the PCM to determine oil temperature is equal to the reference voltage minus the voltage drop across the pull-up resistor. Any circuit faults in the temperature sensor circuits or in the temperature sensor cause the PCM to set a DTC.
Visual Inspection and Diagnostic Pre-checks
Wiring, terminals or connectors Constant velocity joints Differential oil temperature sensor PCM
PINPOINT TEST A : DTC P1888
A1 CHECK THE TEMPERATURE SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
Ignition OFF. Disconnect Differential Oil Temperature Sensor C379. Disconnect PCM C175B. Measure:
Click to display connectors
Positive Lead | Measurement / Action | Negative Lead |
|---|---|---|
C379-1 | Ground | |
C379-2 | Ground |
Is any voltage present?
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.