What it means
Fault on the OFF/ON/START ignition output. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
The OFF/ON/START output provides the ignition-state signal or power used by circuits that need those key states. The module monitors whether the output matches the requested state; this code indicates a fault that may leave dependent circuits powered or unpowered at the wrong time.
Common causes
Most likely first.
- Wiring or relay fault
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
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
How to diagnose it
- Record all module codes and freeze-frame details, identifying whether the fault appears during OFF, ON, or START.
- Use a scan tool to compare the requested OFF/ON/START state with the output status and reports from affected modules.
- Inspect the output wire, connectors, fuse connections, and related relay for damage, corrosion, looseness, or heat marks.
- Test output behavior and relay switching in each commanded state using the manufacturer's circuit procedure.
- If the output circuit is sound, check gateway routing and CAN termination if other modules also report communication faults.
Common fixes
- Repair damaged OFF/ON/START output wiring or connectors.
- Replace a relay or repair a fuse connection only after confirming it is faulty.
- Correct a confirmed gateway routing or configuration fault.
- Repair CAN termination if measurements are outside the manufacturer's specification.
Can I keep driving?
Avoid driving if the ignition output causes stalling, loss of essential electrical functions, or unpredictable power. Even if the vehicle runs normally, the fault can prevent a reliable shutdown or restart.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.