C0403

AWD Oil Filter Reverse Valve Stuck Open

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine Light Is On
Reduced all-wheel drive efficiency
Unusual noises from the transmission area

Causes

Oil contamination
Mechanical valve wear
Foreign particles entering the valve
Poor oil quality or late replacement

How to Fix

Check the oil level and condition in the all-wheel drive system
Change oil and oil filter
Check the operation of the check valve
If necessary, replace the valve or the entire oil filter assembly

Related codes

C0401 C0402 C0404