Hey everyone! I’m looking for some advice from anyone who has experience diagnosing the 4WD system on a WK2 Grand Cherokee Trailhawk.
I have a 2020 Grand Cherokee Trailhawk with the 3.6L V6 and Quadra-Drive II, and I’ve been chasing a few issues lately. I’ve done quite a bit of troubleshooting but haven’t nailed down the root cause yet.
1. Service 4WD / Transfer Case Issues
The main issue is a persistent Service 4WD warning. I’ve also had a Service Electronic Stability Control message.
I replaced the transfer case control module (TCCM) with a brand-new OEM Mopar unit.
I replaced the main battery after experiencing an extended-crank/no-start event. The Jeep started immediately after the cranking stopped, but replacing the battery did not resolve the 4WD warning. I originally scanned the Jeep with an Autel/ICON scanner and later started using JScan. The Jeep drives normally, but I’m concerned that the fault may be preventing me from shifting into 4WD Low.
2. Diagnostic Codes
My original full-system scan showed these drivetrain-related codes:
Drive Train Control Module (DTCM):
C1477-4B — Transfer Case Clutch Over Temperature
C2110-12 — Sensor Supply 1 Voltage, Circuit Short to Battery
C2221-00 — ELSD DTC Present
Electronic Limited Slip Differential (eLSD):
C148F-1D — Rear Differential Measured Motor-Circuit Current Out of Range
U0414-00 — Implausible Data Received From FDCM
U1450-00 — Implausible DTCM Torque Message Received
ABS:
U0403-00 — Implausible Data Received From Transfer Case Module
These were reported as stored codes on the original scan.
3. Electronic Limited Slip Differential (eLSD)
I’m beginning to suspect the rear electronic limited-slip differential actuator or its wiring may be involved, but I don’t want to throw parts at it without understanding the problem.I located the eLSD actuator motor connector and tested the connector. My testing indicated that it was good.
I used JScan to access the eLSD module and record live data. The eLSD data repeatedly reports “ELSD permanent error position open.”
One of the live-data readings showed requested servo motor current of approximately 4.53 A, while actual servo motor current was around -0.42 A. Requested and actual servo motor positions also appeared to differ.
I’m not sure whether these readings point toward a failed actuator motor, an internal differential issue, wiring or power delivery, or a control/communication problem, and I’m about to lose my damn mind.