Pinpoint Test B : DTC P187C:00 And P187D:00: Notes
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
Refer to Four Wheel Drive Systems for schematic and connector information.
Normal Operation
When the ELD MSS is engaged to lock the rear differential, the TCCM sends a PWM signal to the ELD field coil through the differential lock control circuit. This PWM signal is initially 98% duty cycle to lock the differential and then tapers off to a lower duty cycle once the differential is locked. If the differential lock control circuit is open or shorted to ground, the TCCM senses a signal is not reaching the differential and sets a DTC.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P187C:00 | Differential Lock-Up Control Circuit/Open: No Sub Type Information | This DTC sets when the TCCM senses the differential lock control circuit is open. The ELD differential is not engaged. |
| P187D:00 | Differential Lock-Up Control Circuit Low: No Sub Type Information | This DTC sets when the TCCM senses the differential lock control circuit is shorted to ground. The ELD differential is not engaged. |
Possible Sources
- Wiring, terminals or connectors
- TCCM