All wheel drive indicator circuit fault
What it means
B0770. All wheel drive indicator circuit fault. The transfer case control module cannot confirm the drive mode and the body warning light comes on.. This Chevy-enhanced code applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.
Findings, check these first
- Faulty all wheel drive select switch
- Open or short in the all wheel drive indicator circuit
- Corroded transfer case select switch connector
- Faulty transfer case shift control module
- All wheel drive indicator lamp driver failed
Standard procedure
- Confirm the code with a scan tool
- Inspect the all wheel drive select switch and its connector
- Test the all wheel drive indicator circuit for opens and shorts
- Command the all wheel drive indicator with the scan tool and watch the lamp
- Replace the select switch or transfer case shift control module only after circuit tests pass, then clear the code and retest
Look up another code
Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.
Sources and review
Review: checked against the recorded source material.
- B0770 CHEVROLET Code: Meaning, Causes, and Symptoms | OBD2 Codes - OBD2 Codes
live reference page (obd2-codes.co)
Supports: CHEVROLET and GM-family meaning and likely causes for B0770
Fetched directly. B0770 reads "All Wheel Drive Indicator Circuit".
- Code B0770 meaning and causes | OBDII.pro
live reference page (obdii.pro)
Supports: independent corroboration of the GM meaning
Fetched directly. obdii.pro is a separate publisher and gives the GM meaning as: AWD/4WD indicator circuit malfunction More details about the error B0770 and possible reasons for its occurrence.
Last updated 2026-10-10.
Report a correction for B0770. Include your vehicle, the issue and a source if you have one.