Jeep Grand Cherokee Transfer Case Module Replacement in Kirkland, WA: C1403 Code with 4WD and Stability Control Lights

This 2019 Jeep Grand Cherokee Limited came into our Kirkland shop at 121,278 miles with the warning lights for 4WD and stability control on. We traced the lights to a failed transfer case control module, then took care of the fluid problems the inspection turned up.

The diagnosis

We connected our scan tool and pulled two related codes. The drivetrain control module had C1403-92 (transfer case range position sensor performance or incorrect operation), and the ABS module had U0403-00 (implausible data received from the transfer case).

The pre-scan: C1403-92 stored in the drivetrain control module and U0403-00 active in the ABS module, both pointing at the transfer case.

C1403 can be caused by the module, the actuator or a sensor glitch. We tested the module and found that it had failed. See how we narrow down warning lights on our engine diagnostics page.

The repair

We removed the old transfer case control module and installed a new genuine Mopar module. A partner shop handled the programming, and no faults returned on the test drive. More on our drivetrain repair work.

What the inspection found

Our multi-point inspection marked the transmission and drivetrain fluids red because they were dark. The photos show the samples on our fluid tray next to new fluid.

Rear differential fluid (right) on our fluid tray, next to new drivetrain fluid (left).

Transmission fluid sample (right) next to new transmission fluid (left).

The brake fluid failed both the moisture test and the copper corrosion test, so we recommended a flush.

The copper corrosion test strip for the brake fluid, read against the chart. The tech marked it as a fail.

The work performed

• Transfer case control module, with diagnosis and programming: $1,000–$1,550. Genuine Mopar module; programming by a partner shop.

• Transmission fluid and filter service: $1,000–$1,450. Pan off, fluid drained, mating surfaces cleaned, new genuine Mopar pan and filter assembly, refilled with genuine Mopar ZF 8/9-speed fluid, level set with the engine running, leak check and test drive. The pan and filter assembly was the biggest part of this line. Details on our transmission fluid service.

• Drivetrain fluid service: $300–$450. Front and rear differentials (75W-90 full synthetic gear oil) and the transfer case (genuine Mopar ATF+4).

• Brake fluid flush: $150–$225. Old fluid flushed from the master cylinder, calipers and lines, air bled out, road tested. More on our brake fluid flush.

• Multi-point inspection: $125–$250.

What we recommended but didn’t do

The owner held off on three items from the inspection:

• Valve cover gaskets. The gasket was starting to leak. The quote replaced both valve covers with genuine Mopar parts, in the $2,100–$3,100 range.

Under the engine, where the inspection noted the valve cover gasket starting to leak.

• Rear shocks. The right rear was leaking. The quote covered both rear shocks with genuine Mopar parts, in the $800–$1,100 range.

The right rear shock, which the inspection found leaking.

• Oil filter adapter housing. Our note on this quote calls it a common issue on this vehicle, though it wasn’t a problem yet on this one. The quote included an oil and filter change, in the $1,150–$1,650 range.

Everything else checked out: brake pads 5mm front and 8mm rear, tires 8/32” front and 9/32” rear, both air filters good, and the battery tested good at 542 CCA against a 650 CCA spec.

What it cost

The visit landed in the $2,750–$3,850 range, completed October 2026. That covers the transfer case module repair, the transmission, differential and transfer case fluid services, the brake fluid flush and the inspection. The new module and the transmission pan and filter assembly were the two biggest parts costs.

That range reflects a completed historical project, not a current quote.

Questions about this job

What caused the 4WD and stability control lights?

A failed transfer case control module. The code (C1403-92) can come from the module, the actuator or a sensor, and testing showed it was the module.

Did the transfer case module need programming?

Yes. A partner shop programmed the new module, and no faults returned on the test drive.

Why were the fluid services done on the same visit?

The inspection found the transmission and drivetrain fluids dark, and the brake fluid failed both its moisture and copper corrosion tests.

Were the valve cover gasket and oil filter adapter housing replaced?

No. Both were quoted, and the owner held off on this visit. The gasket was only starting to leak, and the note on the housing says it wasn’t a problem yet.

Do you work on Jeeps?

Yes. More on our Jeep repair in Kirkland.

Prepared from our job records for this vehicle: the repair order and technician notes, the multi-point inspection with photos, the scan tool report, the parts list and the final invoice.