P2AF2: Starter Relay C Control Circuit/Open

P2AF2 reports an open or otherwise faulty control line for a third starter relay. Such a relay appears where cranking is split across several switching stages, for instance on stop-start engines. No manufacturer documents P2AF2 publicly. The nearest documented user of relay C is Stellantis, which calls it Starter Relay 3: on Jeep and RAM stop-start models it is the power control relay that cuts the main battery off from the auxiliary one during an auto-start, yet published bulletins only cover its stuck codes P2AF5 and P2AF6. As an analogy for the circuit test, GM treats its tandem starter pinion relay output (P26E4) as open at 200 kΩ or more between signal and ground, after 40 failures in 50 samples of 50 ms, Type B. Shorts to ground and to voltage are P2AF3 and P2AF4.

Medium severity. Can I keep driving?If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.

Symptoms

Stop-start function disabled
Occasional or permanent no-crank
Warning lamp depending on manufacturer

Most likely causes

Broken control wire or unplugged relay connector
Open relay coil
Blown fuse or missing supply to the relay coil
Faulty output driver in the control module

What to check, in order

Start with the simplest. You can tick off each step.

Check the battery voltage
Check the continuity of the wire between the component and the control module.
Try another key, if you have one
Check the fuses and the starter relay
Check the wiring and the signal to the starter motor

Good to know

Repair difficulty: medium

What each character of P2AF2 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
A: Hybrid or air and fuel
F2: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2AF2?

If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.

What causes code P2AF2?

The most common causes are: broken control wire or unplugged relay connector; open relay coil; blown fuse or missing supply to the relay coil.

Related codes

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.