What it means
Starter relay C reports a control circuit low condition. Engine cranking can be inhibited or commanded unintentionally.
At a glance
- Usually lights the check-engine light
How it works
Starter relay C carries the starting-system command from the module to the relay coil. The module sets P2AF3 when it detects the relay C control circuit below its expected level, which can happen with a wire shorted to ground, a shorted coil, or poor connector contact.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in relay coil
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light may be on
- Engine may not crank
- Intermittent starting difficulty
How to diagnose it
- Review freeze-frame and starting-system codes, and note whether the low reading coincides with a no-crank or intermittent start.
- Inspect relay C's connector and control wiring for chafing against ground, corrosion, or loose terminals.
- Check relay C seating and terminal condition using the vehicle's fuse-box diagram to identify the correct relay.
- With the manufacturer's wiring diagram, test the control wire for a short to ground and inspect connector continuity.
- Test relay C's coil and control-circuit response using the manufacturer's procedure to distinguish a shorted coil from a harness fault.
Common fixes
- Clean or repair corroded relay C connector terminals.
- Repair the control wire where its insulation has allowed a short to ground.
- Replace relay C if its coil is internally shorted.
Can I keep driving?
The vehicle may not crank or may start intermittently, so avoid shutting it off where a restart failure could leave you stranded. If it starts and the starter disengages normally, a short trip may be possible, but arrange prompt diagnosis.
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.