What it means
The control module monitors whether starter relay B switches on when commanded. It sets this code when the relay does not provide the expected switched output.
At a glance
- Usually lights the check-engine light
How it works
Starter relay B should close when the module requests its starter-related circuit. P26F3 sets when the module does not detect the expected switched output from relay B, which may cause starting or stop-start problems.
Common causes
Most likely first.
- Starter relay contacts fail to close
- Relay control circuit fault
Symptoms
- Engine may crank slowly or fail to start
- A starter or powertrain warning light may appear
- Stop-start function may be unavailable
How to diagnose it
- Check freeze-frame data and scan-tool commands to see whether relay B was commanded on when the fault occurred.
- Inspect relay B's fuse, socket, and terminals for corrosion, looseness, heat damage, or loss of supply.
- Check whether the engine cranks and whether relay B output responds to a command, using the manufacturer's procedure.
- Test relay B contacts and its control wire for an open or failed relay operation.
- If relay B and its wiring pass, check the associated starter circuit and module output for an open.
Common fixes
- Clean and secure relay B socket terminals and its supply connection.
- Replace relay B if it fails to close when commanded.
- Repair a broken relay B control wire or connector.
- Repair a confirmed open in the associated starter circuit or module output.
Can I keep driving?
If the engine cranks slowly or will not start, avoid repeated attempts to prevent draining the battery; stop-start may also be disabled. If the engine runs normally, limit driving to necessary trips because the fault may prevent restarting after you switch the engine off.
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.