2021-2023 Jeep Wrangler Hybrid System Fault TSB

Symptoms of the Jeep Wrangler Hybrid System Fault

Owners of 2021-2023 Jeep Wrangler models may experience a "Service Hybrid Electric Vehicle System" message appearing in the instrument panel cluster (IPC). This warning can be accompanied by the vehicle shaking during a cold start. Additionally, a noticeable noise might be heard near the P2 motor. These symptoms indicate a potential problem with the hybrid electric vehicle system.

Fault Codes (DTCs)

When these symptoms occur, a diagnostic scan of the vehicle's systems may reveal specific Diagnostic Trouble Codes (DTCs). The manufacturer communication S2208000154 Rev. A identifies the following codes:

• U0287-00: Lost Communication With Transmission Fluid Pump Set In The TCM (Transmission Control Module).
• B273C-00: Digital Crash Input in the HCP (Hybrid Control Processor).

These codes point to communication issues and potential electrical faults within the hybrid system.

Diagnosis of the Hybrid System Issue

The "Service Hybrid Electric Vehicle System" message and associated symptoms in the 2021-2023 Jeep Wrangler are often traced back to damage in the PIM to P2 High Voltage (HV) wiring harness. This damage can manifest as a rub-through or kink, particularly near the transmission driveshaft CV joint shield. Such damage can lead to two primary issues.

Firstly, the physical damage to the HV harness can directly cause the communication loss with the Transmission Fluid Pump, triggering DTC U0287-00. Secondly, a damaged HV harness can induce electrical noise into the low voltage harness. This inductive noise can be detected on the R414 circuit using an oscilloscope, appearing as voltage spikes. This interference can lead to the B273C-00 DTC, indicating a digital crash input in the Hybrid Control Processor. Technicians are advised to inspect the PIM to P2 wiring harness carefully for any signs of rub-through or other damage. The presence of electrical noise on the R414 circuit further confirms the inductive interference. This diagnostic process helps pinpoint the exact cause of the Jeep Wrangler hybrid system fault and related performance issues.

Repair Procedure Summary

If damage to the PIM to P2 High Voltage wiring harness is identified, the repair involves replacing the affected high voltage wiring harness. Before any work is performed on the HV electrical system, it is crucial to follow all safety procedures for powering down and isolating the HV components. This ensures technician safety and prevents further damage to the vehicle.

After the replacement, technicians must clear all Diagnostic Trouble Codes (DTCs). The vehicle should then be started to verify that it runs smoothly and that the "Service Hybrid Electric Vehicle System" warning message is no longer displayed in the IPC. A test drive is recommended to confirm that the DTCs and original symptoms, including the Jeep Wrangler hybrid system fault, do not return.

Important Warnings

This manufacturer communication, S2208000154 Rev. A, serves as a record of past experiences and does not authorize warranty repairs. It provides insights into known issues but does not conclude what is specifically wrong with an individual vehicle. The document states: "This document does not authorize warranty repairs. This communication documents a record of past experiences. STAR Online does not provide any conclusions about what is wrong with the vehicle. Rather, it captures all previous cases known that appear to be similar or related to the vehicle symptom / condition. You are the expert, and you are responsible for deciding on the appropriate course of action." Owners should be aware that this document is for diagnostic guidance for technicians.

Source: NHTSA ID: 11014250