2019 Jeep Wrangler DTCM Update for 4WD System Fault C147B-92

Owners of the 2019 Jeep Wrangler may experience a Malfunction Indicator Lamp (MIL) illumination accompanied by specific 4WD system issues. This concern is addressed by Technical Service Bulletin (TSB) 08-364-26, which outlines a software update for the Drivetrain Control Module (DTCM).

This bulletin applies to 2019 Jeep Wrangler (JL) models equipped with the 2.0L DOHC DI Turbo PHEV Engine (Sales Code ECX) and one of several 4WD system sales codes: Command-Trac Part Time 4WD system (DHN), 2.72:1 Select-Trac Full Time 4WD SYS (DHP), 4:1 Rock-Trac HD Part Time 4WD SYS (DHW), or 4:1 Rock-Trac HD Full Time 4WD SYS (DHF). The bulletin is applicable to vehicles in North America, South America, Enlarged Europe, Middle East & Africa, India & Asia Pacific, and China markets.

Symptoms

If your 2019 Jeep Wrangler 4WD system fault is present, you may notice a Malfunction Indicator Lamp (MIL) illuminated on your dashboard. Additionally, customers may report one or more of the following observations:

• "4WD system warning lights, service messages, or flashing indicators are displayed in the Instrument Panel Cluster (IPC)."
• "The vehicle does not engage 4WD properly."

Fault Codes / DTCs

The primary Diagnostic Trouble Code (DTC) associated with this 2019 Jeep Wrangler 4WD system fault is:

• C147B-92 - Front Axle Disconnect Sensor Performance or Incorrect Operation

Cause

The root cause for these symptoms and the C147B-92 DTC is identified as an issue requiring a Drivetrain Control Module (DTCM) update.

Repair Procedure Summary

The resolution for this 2019 Jeep Wrangler 4WD system fault involves reprogramming the Drivetrain Control Module (DTCM) with the latest available software. Technicians will first connect a battery charger to maintain voltage during the flash process. After the DTCM is successfully reprogrammed, all Diagnostic Trouble Codes (DTCs) that may have been set in any module due to the reprogramming will be cleared using the wiTECH application.

Required Tools or Parts

To perform the DTCM reprogramming, a wiTECH scan tool or an equivalent diagnostic tool is required.

Important Warnings

Technicians performing the update outlined in TSB 08-364-26 must adhere to specific battery voltage requirements:

• Install a battery charger to ensure battery voltage does not drop below 13.2 volts.
• Do not allow the charging voltage to climb above 13.5 volts during the flash process.
• If the flash process is interrupted or aborted, the flash should be restarted.

Warranty Information

This DTCM software update is reimbursable under the provisions of the vehicle's warranty. Dealers should use failure code CC (Customer Concern) if the customer's reported symptom matches those described in this Technical Service Bulletin. When using failure code CC, the 3C's (customer's concern, cause, and correction) must be provided for processing the flash/reprogramming conditions.

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Source: NHTSA ID: 11038524