OBD-II code · Network
U042E Invalid Data Received From Generator A Control Module
A receiving module detected implausible data from generator (alternator) control module A. Field excitation, output current or voltage values fail plausibility checks and are rejected.
Is it safe to drive with U042E?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyModule internal fault or sensor input drift
- PossibleSoftware version mismatch after replacement
- Less likelyGateway module routing CAN messages incorrectly
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Generator Module A
Related codes
- U044DInvalid Data Received From Generator B Control Module
- U042BInvalid Data Received From Chassis Control Module A
- U042CInvalid Data Received From Chassis Control Module B
- U042DInvalid Data Received From Active Vibration Control Module
- U042FInvalid Data Received From Camshaft Position Control Module
- U0430Invalid Data Received from Tire Pressure Monitoring Sensor
- U0431Invalid Data Received from Body Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.