Normal Operation
WARNING: This page is about a different car, the 2014 Ford F-150. 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 P185B:00 (Differential Lock-Up Indicator Circuit Low: No Sub Type Information) - When not in locking mode, the TCCM C2371A-20 senses the indicator circuit is shorted to ground and the indicator is always illuminated. This DTC should not set for an open circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- TCCM