P0694🔧 Engine cooling (electric radiator fan)Stop and fix promptly

P0694: Cooling Fan 2 Relay Control Circuit High (Meaning, Causes, Fixes)

Reviewed 2026-10-25 · Based on 2 cited source(s)

What P0694 means

Many cars have two electric fans that pull air through the radiator when the car isn't moving fast enough to cool it, such as in stop-and-go traffic, on hot days or with the A/C on. The powertrain computer (PCM) switches the fans on and off based on the engine coolant temperature sensor. OBD-Codes.com explains that the PCM turns a fan on by grounding its relay's control circuit: that circuit sits near battery voltage when the fan is off and near zero when the fan is commanded on. P0694 is set when the PCM sees the voltage stay high while cooling fan 2 is commanded on. RepairPal defines the code a little more broadly as 'Fan 2 Control Circuit High' and says the PCM sets it when it can't control the cooling fan as desired. It is a generic code for 1996 and newer vehicles, and repair steps vary by make and model. The sources differ on symptoms: OBD-Codes.com lists engine overheating and the check engine light, while RepairPal also says the fans may stay on all the time and the A/C may not work. They also differ on causes: OBD-Codes.com names the fan 2 relay, a blown fan 2 fuse and, rarely, the PCM, while RepairPal adds a failed fan control module, a failed fan motor and wiring problems. P0693 is the matching 'circuit low' code for fan 2, and P0691 and P0692 are the same codes for cooling fan 1.

Severity: can I keep driving?

Stop and fix promptly

Get it fixed soon. OBD-Codes.com says overheating from cooling fans that don't run is very probable, so use caution driving and repair it as soon as possible. RepairPal rates P0694 Urgent, meaning immediate action is needed.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Faulty cooling fan 2 relay (OBD-Codes.com says this is the most common cause in the author's experience; RepairPal)
  2. Blown cooling fan 2 fuse (OBD-Codes.com)
  3. Failed cooling fan motor (RepairPal)
  4. Failed engine cooling fan control module (RepairPal)
  5. Wiring problem (RepairPal)
  6. Faulty engine computer (PCM), which OBD-Codes.com says is rare (OBD-Codes.com, RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Check the cooling fan fuse first (your owner's manual or the fuse box lid shows which one), and replace it only with one of the same amperage.
  2. OBD-Codes.com suggests a simple relay test: find another relay in the same box that is identical in every way, swap the two, clear the code and drive. If the code doesn't come back, replace the fan relay; if it does, suspect the wiring, fan or computer.
  3. Be absolutely sure the relay you swap in is identical. OBD-Codes.com warns that the wrong relay can damage the PCM, and that some Nissan relays look the same apart from color and fit the same socket but are different.
  4. Use caution around hot parts and fans that can start on their own, and watch the temperature gauge while this code is set.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The engine is overheating or the temperature gauge is climbing
  • A swapped or new relay doesn't clear the code
  • You can't find an identical relay to swap in
  • Your car uses a cooling fan control module instead of simple relays

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0694?

Only with care. OBD-Codes.com says overheating from cooling fans that don't run is very probable and it should be repaired as soon as possible, and RepairPal rates it Urgent. Keep an eye on the temperature gauge and stop if it climbs.

What is the most common cause of P0694?

OBD-Codes.com's author says a faulty cooling fan relay is the most common cause in their experience. RepairPal also lists the fan motor, a fan control module, wiring and the PCM.

What's the difference between P0693 and P0694?

Both are about the cooling fan 2 relay control circuit. Per OBD-Codes.com, P0693 means the voltage is low while the fan is off, and P0694 means the voltage stays high while the fan is commanded on.

How much does it cost to fix P0694?

Neither source gives a repair cost for P0694. A fuse or relay is a much smaller job than a fan assembly or engine computer, so find the cause before buying parts.

Sources

  1. OBD-Codes.com: P0694 Cooling Fan 2 Relay Control Circuit High (Daniel Young, ASE Master Technician)
  2. RepairPal: P0694 Fan 2 Control Circuit High (rated Urgent)

Last reviewed 2026-10-25. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.