2024 Jeep Wrangler PCM Update TSB 08-142-24

Owners of certain 2024 Jeep Wrangler vehicles may experience issues indicated by a Malfunction Indicator Lamp (MIL) illumination, commonly known as the 'Check Engine Light on'. This can also be accompanied by the vehicle running rough. This TSB, identified as TSB 08-142-24, provides a solution through a software update for the Powertrain Control Module (PCM).

This Jeep Wrangler PCM update specifically targets vehicles built on or before February 01, 2024 (MDH 0201XX), equipped with the 3.6L V6 VVT Engine Upgrade 1 (Sales Code ERC).

Symptoms

Owners may observe a Malfunction Indicator Lamp (MIL) illumination on the dashboard. Additionally, the vehicle might display a 'Check Engine Light on' message and exhibit a 'vehicle runs rough' condition. These symptoms are often accompanied by specific Diagnostic Trouble Codes (DTCs) stored in the vehicle's computer system.

Fault Codes / DTCs

If your 2024 Jeep Wrangler is affected, a scan tool may reveal one or more of the following DTCs:

Code	Description
P1129	Closed Loop Fueling Not Achieved - Bank 2 Upstream
P0158	O2 Sensor 2/2 Circuit High
P0152	O2 Sensor 2/1 Circuit High
P2504	Charging System Output High
P0563	Battery/system Voltage High (eTorque)

Diagnosis

To diagnose the issue, a technician will use a scan tool, such as wiTECH, to verify that all related systems are functioning correctly. If the vehicle exhibits the symptoms and DTCs listed in TSB 08-142-24, the repair procedure outlined in this bulletin should be followed. Any other DTCs or symptom conditions not covered by this TSB should be addressed separately.

Repair Procedure Summary

The primary repair involves reprogramming the Powertrain Control Module (PCM) with the latest available software. This Jeep Wrangler PCM update is a straightforward process that requires specific attention to detail:

1. PCM Reprogramming: The PCM is reprogrammed using the wiTECH Diagnostic Application to install the most current software version. If any issues arise during this process, a ticket should be submitted to the Helpdesk.
2. DTC Clearing: After the reprogramming, all Diagnostic Trouble Codes (DTCs) that may have been set in any module due to the reprogramming process must be cleared. The wiTECH application will automatically facilitate this step.
3. Cam Crank Relearn: A 'Cam Crank Relearn' routine must be performed. This routine can be found within the PCM 'Misc Functions' section of the wiTECH tool.

Required Tools or Parts

• wiTECH or Equivalent: A diagnostic scan tool capable of performing module reprogramming and diagnostic functions.

Important Warnings

• Battery Voltage: During the flash process, it is crucial to install a battery charger to maintain the battery voltage between 13.2 and 13.5 volts. The charging voltage must not drop below 13.2 volts or climb above 13.5 volts.
• Interrupted Flash: If the flash process is interrupted or aborted for any reason, it must be restarted from the beginning.

Owner Action

If your 2024 Jeep Wrangler is experiencing any of the symptoms described, such as a 'Check Engine Light on' or rough running, and you suspect it might be related to the issues covered by TSB 08-142-24, it is recommended to visit an authorized Jeep dealership. The repair, which involves a PCM software update, is reimbursable within the provisions of the warranty and typically takes about 0.3 hours of labor.

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Source: NHTSA ID: 11002074