HomeTrouble CodesP0692

P0692 — Fan 1 Control Circuit High

Generic OBD-II · all makesPowertrain (engine & transmission)

P0692 indicates that the powertrain control module (PCM) has detected a high voltage condition in the control circuit for cooling fan 1. This typically means the circuit is shorted to battery voltage or a component is failing, not that the PCM itself is faulty.

Symptoms

What causes it — most likely first

1. Short to battery voltage in fan 1 control circuit

A wire in the fan control circuit has rubbed through and is contacting a 12V source, causing the high voltage reading.

2. Faulty cooling fan relay (stuck closed or internally shorted)

A relay that fails in the closed position or has an internal short can supply constant voltage to the fan control circuit.

3. Damaged cooling fan motor (internal short)

An internal short in the fan motor can backfeed voltage into the control circuit, triggering the high voltage code.

4. Corroded or damaged connector at fan or relay

Moisture or corrosion in the electrical connectors can create unintended paths for voltage.

5. PCM internal fault (rare)

In very rare cases, a failed driver transistor inside the PCM can cause a high voltage condition, but this is the least likely cause and should only be considered after all other possibilities are ruled out.

How it's diagnosed

  1. Verify the code and check for any related fan or cooling system codes.
  2. Inspect the fan 1 relay and its socket for signs of burning, corrosion, or melted plastic.
  3. With the ignition off, disconnect the fan motor connector and measure resistance; compare to specifications (usually a few ohms).
  4. Check for voltage at the fan control wire (PCM side) with key on; if voltage is present when fan should be off, trace the short to voltage.
  5. Test the relay by swapping with an identical relay (e.g., fan 2 relay) and see if the code moves or changes.
  6. If all wiring and components test good, perform a PCM output test with a scan tool to verify the PCM can command the fan; only then consider a PCM issue.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Can I just replace the PCM to fix P0692?

Replacing the PCM is almost never the correct fix for P0692. The code means the PCM detected a high voltage in the fan control circuit, which is usually caused by a shorted wire, bad relay, or faulty fan motor. Replacing the PCM without addressing the underlying circuit problem will not fix the issue and may damage the new PCM.

Will a bad cooling fan relay cause P0692?

Yes, a relay that is stuck closed or has an internal short to the coil supply can cause a high voltage condition on the control circuit, triggering P0692. This is one of the most common causes.

Is it safe to drive with P0692?

It depends. If the fan runs continuously, the engine may not overheat but the fan motor or relay could fail completely. If the fan does not run, the engine can overheat quickly, especially in stop-and-go traffic. It is best to diagnose and repair the issue promptly.

Do I need a scan tool to diagnose P0692?

A basic OBD-II scanner can read the code, but a more advanced scan tool that can command the fan on/off and view live data is very helpful for diagnosis. However, you can still test the relay and wiring with a multimeter.