OBD-II code · Network
U044D Invalid Data Received From Generator B Control Module
A receiving module detected implausible data from generator (alternator) control module B. Field excitation, output current or voltage values fail plausibility checks and are rejected.
Is it safe to drive with U044D?
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 B
Related codes
- U042EInvalid Data Received From Generator A Control Module
- U044AInvalid Data Received From Serial Data Gateway Module D
- U044BInvalid Data Received From Battery Energy Control Module C
- U044CInvalid Data Received From Hybrid/EV Battery Inductive Charging Module
- U044FInvalid Data Received From Mirror Control Module B
- U0451Invalid Data Received From Serial Data Gateway Module E
- U0452Invalid Data Received From Restraints Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.