U042BInvalid Data Received From Chassis Control Module A
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- Chassis control module A is a generic name for a controller that coordinates chassis functions, and the job behind the letter varies by brand. GM's documents give one concrete owner: the 2020 ten-speed transmission controller (20OBDG03A) treats the integrated chassis control module (ICCM) as chassis control module A and watches its frame $1F7; an L20 engine controller of 2016 also listens to this module. U042B is set when such frames keep arriving but fail content checks, as opposed to U012A, where they stop. No manufacturer documents U042B publicly, so thresholds and lamp behaviour remain open; GM rates the missing-frame case Type C on the transmission and Type B on the engine. Expect chassis or stability messages and a degraded function; a MIL depends on which controller stores it. U042C is module B.
- What you may notice
- Chassis, stability or suspension warning
- Chassis functions such as damping or traction aids limited
- Likely causes
- PossibleSoftware fault in the chassis module or the receiving controller
- PossibleLow voltage or reset of the chassis module during operation
- RareChassis control module A faulty
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.