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, the TCCM sends a voltage signal through the MSS to ground pulling the voltage low. When the TCCM senses the voltage is low it activates the ELD .
- DTC P185A:00 (Differential Lock-Up Input Switch Circuit High: No Sub Type Information) - When not in locking mode, the TCCM senses whether the ELD mode switch circuit has low voltage and if the differential is always engaged. This DTC will not set unless the MSS is set to 2H or OFF. If the ELD is functioning normally, the differential will immediately lock when the MSS is activated and the ELD operating conditions are qualified. This DTC will only display during the self-test function.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- MSS
- TCCM