2024 Jeep Wrangler PCM Update for MIL and DTCs

Stellantis has issued Technical Service Bulletin (TSB) 18-050-24, dated May 21, 2024, to address various performance concerns in certain 2024 Jeep Wrangler vehicles. This bulletin specifically applies to vehicles built on or before December 19, 2023, equipped with the 3.6L V6 VVT Engine Upgrade 1 (Sales Code ERC). The primary solution for these issues is a software update for the Powertrain Control Module (PCM).

This TSB aims to resolve instances where customers experience a Malfunction Indicator Lamp (MIL) illumination, along with specific Diagnostic Trouble Codes (DTCs). Beyond warning lights, the update also targets general drivability issues and other software enhancements to improve overall vehicle operation. Owners experiencing these symptoms should seek a Jeep Wrangler PCM update at an authorized dealership.

Symptoms

Owners of affected 2024 Jeep Wrangler vehicles may notice one or more of the following symptoms:

• Illumination of the Malfunction Indicator Lamp (MIL).
• The engine running roughly.
• A "Service Transmission" message appearing due to clutch slip detection with the transfer case in neutral.
• Transfer case mis-shift during flat towing, specifically when the engine is running, the clutch pedal is up, and the transmission is in gear.

Fault Codes / DTCs

This TSB specifically addresses the following Diagnostic Trouble Codes (DTCs) that may be set in conjunction with MIL illumination:

Code	Description
P1129	Closed Loop Fueling Not Achieved-Banks 2 Upstream
P0158	O2 Sensor 2/2 Circuit High
P0152	O2 Sensor 2/1 Circuit High
P2504	Charging System Output High
P0563	System Voltage High

Trigger Conditions / Diagnosis

Technicians should use a wiTECH scan tool with appropriate diagnostic procedures to verify all related systems are functioning correctly. If any DTCs or symptom conditions other than those listed in TSB 18-050-24 are present, they should be recorded and addressed before proceeding with this bulletin. The presence of the listed symptoms or DTCs indicates the need for a Jeep Wrangler PCM update.

Important Warnings

During the repair procedure, specific precautions must be taken to ensure a successful PCM flash:

• Install a battery charger to maintain battery voltage above 13.2 volts throughout the process. Do not allow the charging voltage to exceed 13.5 volts.
• If the flash process is interrupted or aborted for any reason, it must be restarted from the beginning.

Repair Procedure Summary

The repair for TSB 18-050-24 involves reprogramming the Powertrain Control Module (PCM) with the latest available software. This is a standard flash update that requires specialized diagnostic equipment. After the PCM is reprogrammed, all Diagnostic Trouble Codes (DTCs) stored in any module must be cleared. The wiTECH application will automatically present all DTCs for clearing once the flash is complete.

Required Tools or Parts

To perform this service, technicians will require:

• A wiTECH diagnostic tool or equivalent.
• A battery charger to maintain stable voltage during the reprogramming process.

Owner Action

If your 2024 Jeep Wrangler is experiencing any of the symptoms or DTCs mentioned in TSB 18-050-24, you should contact an authorized Stellantis dealership. The dealer will diagnose the issue and perform the necessary PCM software update. This repair is reimbursable under the provisions of your vehicle's warranty. The labor operation number for this service is 18-19-06-HX, with an estimated labor time of 0.3 hours.

NHTSA ID: 11001282