What it means
Fault on the ignition ON 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 ignition ON output supplies or signals power for circuits that should operate while the ignition is on. The module monitors whether this output follows the requested state; this code indicates a fault on the ON line, which can interrupt systems that depend on ignition-on power.
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, noting whether the fault appears after switching the ignition on or while driving.
- Use a scan tool to compare the commanded ON state with the reported output and identify which modules lose power or communication.
- Inspect the ignition ON output wire, connectors, fuse connections, and related relay for breaks, corrosion, looseness, or heat damage.
- Measure the output in the commanded ON state and test relay operation according to the manufacturer's circuit procedure.
- If the circuit passes, check gateway routing and CAN termination if other modules report communication faults.
Common fixes
- Repair damaged ignition ON wiring or a faulty connector.
- Replace a confirmed faulty relay or repair its fuse connection.
- Correct a confirmed gateway routing or configuration fault.
- Repair CAN termination if it is outside the manufacturer's specification.
Can I keep driving?
Avoid driving if ignition-powered safety or engine systems cut out, or if the vehicle stalls or behaves unpredictably. If it runs normally, keep use limited because the ON output may fail and disable dependent functions.
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.