C140F Final drive control module fault that disables 4WD shifting (Jeep)

Jeep C140F, Service 4WD

Monitor

Jeep's bulletin describes a Service 4WD lamp and a transfer case that will not shift, not a loss of normal driving.

Source: how we rate severity

C140F in short

On Jeep Grand Cherokees and Commanders, C140F means the final drive control module has a fault, and the Service 4WD lamp is on. The transfer case may stop shifting into 4WD Low or Neutral. Jeep's fix is a module software reflash. The vehicle usually drives normally in two-wheel drive.

The final drive control module runs the transfer case motor. C140F stored in its memory lights Service 4WD.

Jeep's bulletin has the dealer check the software level and reflash it. Owners report it after the N23 recall software, with codes returning after clearing.

Pick your make

C140F is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. FDCM software

    Supported by vehicle data
    Why it ranks here
    Bulletin 21-022-14 reflashes the FDCM for C140F.
    What would change this
    Rises if software out of date.

  2. Transfer case motor or wiring

    Possible — needs testing
    Why it ranks here
    An owner had a motor replaced with codes C1405 and C140F still active.
    What would change this
    Rises if reflash does not help.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Ask a dealer to check the FDCM software against bulletin 21-022-14.

    Low risk

Symptoms

  • Service 4WD lamp on
  • Transfer case will not shift to 4WD Low or Neutral

How to fix

On your vehicle

Jeep

  • 21-022-14Status unverified

    4WD lamp with C140F in FDCM

    2008grand-cherokee · issued · NHTSA 10141220

    Check FDCM software and reflash.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 21-022-14 REV. AStatus unverified

    4WD lamp with C140F in FDCM (rev A)

    2006grand-cherokee · issued · NHTSA 10141242

    Revised version of the FDCM reflash bulletin.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

No curated relationships for C140F yet.

All Drivetrain, 4WD and AWD codes

Sources and review

  1. Jeep 21-022-14: 4WD Lamp Illuminated and Diagnostic Trouble Code C140F Active in Final Drive Control Modu — NHTSA manufacturer communications (flat file, NHTSA ID 10141220)
  2. NHTSA complaint ODI 10559323: 2006 Jeep Grand Cherokee, C140F after N23 recall — NHTSA Office of Defects Investigation
  3. Jeep 21-022-14 REV. A: 4WD Lamp Illuminated and Diagnostic Trouble Code C140F Active in Final Drive Control Modul — NHTSA manufacturer communications (flat file, NHTSA ID 10141242)
  4. NHTSA complaint ODI 10559027: 2006 Jeep Grand Cherokee, C1406 C1405 C140F — NHTSA Office of Defects Investigation
Last reviewed
Written by
Saurabh K.
Editorial review
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