OBD-II code · Network
U040B Invalid Data Received From Exhaust Gas Recirculation Control Module A
A receiving module detected implausible data from EGR control module A. Valve position, flow or temperature values fail plausibility checks against other inputs and are rejected.
Is it safe to drive with U040B?
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
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Egr Module A
Related codes
- U040CInvalid Data Received From Exhaust Gas Recirculation Control Module B
- U0408Invalid Data Received from Vehicle Immobilizer Control Module
- U0409Invalid Data Received from Vehicle Security Control Module
- U040AInvalid Data Received From Air Conditioning Control Module
- U040DInvalid Data Received From Turbocharger/Supercharger Control Module A
- U040EInvalid Data Received From Turbocharger/Supercharger Control Module B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.