Normal Operation
WARNING: This page is about a different car, the 2012 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
When the MSS is engaged to lock the rear differential, a PWM signal is sent to the ELD field coil by the TCCM through the differential lock control circuit. This PWM signal is initially 98% duty cycle to lock the differential and decreases to 40% duty cycle once the differential is locked. If the differential does not lock, the TCCM continues to send the signal for a set amount of time. Once the differential is locked, the indicator will illuminate steady.
- DTC P185D:00 (Differential Lock-up Control Circuit Performance: No Sub Type Information) - The TCCM sends a signal to the lock up solenoid to lock the differential. After several unsuccessful attempts, the TCCM sets this DTC alerting the driver the ELD is inoperative. Fault may be due to a wheel speed condition or due to a mechanical failure within the driveline/axle subsystem.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- ELD field coil