What P0693 means
The engine module switches the radiator fan relays (or the input of a PWM fan module) through output drivers and checks each control circuit electrically.
How the engine computer detects it
GM sets a short to ground or voltage at 0.5 Ω or less after 50 of 63 samples, with the lamp after two trips; GM Europe's 2011 Saab 9-5 covers P0691–P0696 with relay assignments, the Saab 9-4X's PWM fan module reacts within 1 s. P0693 means the fan 2 control circuit is shorted to ground; Ford's 2023 diesel uses it for its auxiliary fan relay and also includes an open circuit (0.5 s).
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light (GM after two trips)
- Fan runs constantly or not at all, depending on circuit design
- Rising coolant temperature in traffic or with A/C on
- A/C may be switched off to protect the engine
Common causes
- Control wire to fan relay or module shorted to ground (chafing) Most likely
- Water or corrosion in fan or relay connector Most likely
- Fan relay faulty (coil shorted or low-resistance) Possible
- Engine module driver faulty Less likely
How to diagnose P0693
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: cooling fan relay, fan control circuit, engine control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 6
- Computer and output circuits
- 93
- Specific fault
Questions drivers ask
Can I drive with code P0693?
Carefully, and keep an eye on the temperature gauge. Without a working fan the engine can overheat in traffic or at idle. If the gauge climbs toward hot, pull over and switch the engine off.
Will my car pass an emissions inspection with P0693?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0693 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0693 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: easy. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.