2024-2025 Jeep Compass PCM Wiring Harness Issue TSB 08-086-25

Owners of 2024-2025 Jeep Compass vehicles may encounter issues related to the Powertrain Control Module (PCM) wiring harness. This problem, identified in Technical Service Bulletin (TSB) 08-086-25 and also released as Rapid Service Update (RSU) 25-046, specifically affects vehicles equipped with the 2.0L I4 Turbo Diesel Engine with Engine Stop/Start (Sales Code EBS) and the 6-Speed C635 Manual Transmission (Sales Code DE1). The core issue involves the PCM wiring harness making contact with the PCM bracket, leading to potential damage.

Symptoms

Customers experiencing this issue will typically observe a "Malfunction Indicator Lamp (MIL) illumination" on their dashboard. In more severe cases, owners may also report that the "Vehicle will not start." These symptoms are directly linked to damage within the Jeep Compass PCM wiring harness.

Fault Codes / DTCs

When the PCM wiring harness is damaged, the vehicle's diagnostic system will set specific Diagnostic Trouble Codes (DTCs). These codes help technicians pinpoint the nature of the electrical fault:

Code	Description
P0235	Turbocharger Pressure Sensor Signal Circuit Short To Ground
P0521	Plausibility Monitoring Between Two Engine Oil Pressure Switch Inverted Mounting
P0253	Metering Unit Electrical Failure Circuit Short To Ground

Cause of the Jeep Compass PCM Wiring Harness Issue

The root cause of these electrical problems is physical damage to the PCM wiring harness. This damage occurs because the harness rubs against the PCM bracket, leading to wear and potential short circuits. This friction can compromise the integrity of the wiring, affecting critical sensor signals and overall engine operation.

Diagnosis

To determine if a vehicle is affected by TSB 08-086-25 or RSU 25-046, technicians should first check the vehicle's VIN in the VIP system or the RSU VIN list. If the VIN is listed, the repair procedure should be performed. Even if a vehicle is not on the VIN list but exhibits the described symptoms, the repair procedure is recommended. Diagnostic work may involve using a wiTECH diagnostic tool or equivalent equipment to confirm the presence of the listed DTCs.

Repair Procedure Summary

The repair process outlined in TSB 08-086-25 focuses on inspecting and, if necessary, repairing or replacing the damaged PCM wiring harness. The steps involve:

1. Harness Measurement: Technicians first measure the length of the PCM harness from the PCM connector to the channel edge, as illustrated in Fig. 1 and Fig. 2 of the bulletin.
2. Damage Assessment: The harness is then inspected for any damage or if its length exceeds 250 mm (9.8 inches). If damage is present, or if the harness is too long, further steps are taken.
3. Harness Replacement (if damaged): If the wiring harness is found to be damaged, it is replaced with a new one.
4. Harness Taping (if not damaged but too long/rubbing): If the harness is not damaged but is identified as a potential rubbing point, it is taped up to prevent future wear, as shown in Fig. 3.
5. Routing and Securing: The harness is carefully routed through a designated routing clamp, and the clamp is locked to ensure the harness is securely positioned and cannot rub against the PCM bracket again (Fig. 4).
6. DTC Clearance: Finally, all stored Diagnostic Trouble Codes (DTCs) are cleared from the vehicle's system.

Required Tools or Parts

For diagnosis and repair, technicians may utilize a wiTECH diagnostic tool or an equivalent system. Specific replacement parts for the Jeep Compass PCM wiring harness include:

• 68639016AA: Engine wiring harness - M6 MT
• 68607466AA: Engine wiring harness - H6 MT

Important Warnings

This Technical Service Bulletin (TSB) 08-086-25 and Rapid Service Update (RSU) 25-046 explicitly state that "All repairs are reimbursable within the provisions of warranty." Owners should ensure their vehicle is within the warranty period to avoid out-of-pocket expenses for this repair.

What Owners Should Do

If your 2024-2025 Jeep Compass is exhibiting a "Malfunction Indicator Lamp illumination" or experiencing starting difficulties, and you suspect a Jeep Compass PCM wiring harness issue, it is recommended to contact your authorized Jeep dealership. Provide them with your vehicle's symptoms and mention TSB 08-086-25 or RSU 25-046. The dealership will be able to perform the necessary diagnostic checks and repairs under warranty.

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Source: NHTSA ID: 11015894