A receiving module detected implausible data from the second engine/powertrain control module (ECM/PCM B — used on V-engines with one ECU per bank or master/slave architectures). Engine torque, RPM or load values fail plausibility checks and are rejected.
Medium severity. Can I keep driving?It depends on which control module has dropped out. If it affects the engine, brakes, or steering, do not continue your trip: call for roadside assistance.
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
Most likely causes
- Module internal fault or sensor input drift
- Software version mismatch after replacement
- Gateway module routing CAN messages incorrectly
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It can trigger limp mode.
- It affects emissions.
What each character of U0442 means
- U: Communication network
- 0: Generic code: same on every make
- 4: Subsystem depends on the code range
- 42: Specific fault in that system
Frequently asked questions
Can I keep driving with code U0442?
It depends on which control module has dropped out. If it affects the engine, brakes, or steering, do not continue your trip: call for roadside assistance.
What causes code U0442?
The most common causes are: module internal fault or sensor input drift; software version mismatch after replacement; gateway module routing CAN messages incorrectly.
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.