P0694 – Fan 2 Control Circuit High (OBD2)
P0694 means "Fan 2 Control Circuit High". The voltage in the radiator cooling fan circuit is above the permitted maximum. For most sensors this points to an open signal or ground wire – the signal "floats" up to the reference voltage – or to a short to voltage.
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P0694 quick summary
| Fault code | P0694 |
|---|---|
| Meaning | Fan 2 Control Circuit High |
| System | Powertrain (Engine & Transmission) |
| Vehicles | Generic OBD2 |
| Severity | High |
| Can I drive? | Only with care. Without a working fan the engine can overheat in traffic – watch the temperature gauge and avoid queues until it is fixed. |
| Repair cost | €20 – €600 |
How the radiator cooling fan is controlled
The electric cooling fan pulls air through the radiator when the vehicle is slow or stationary; these codes mean the fan control, its circuits or its speed are faulty.
Most cars have one or two electric fans controlled by relays or by a fan control module that varies the speed. The engine control unit switches them on depending on coolant temperature, air conditioning pressure and sometimes after the engine is switched off. Some engines with a belt-driven viscous fan have a speed sensor and an electrically controlled clutch.
Codes P0480–P0485 and P0691–P0696 report faults in the fan control circuits, over-current and power/ground problems; P0493–P0495 and P0526–P0529 cover fan speed and the fan speed sensor.
A fan that does not run leads to overheating in traffic and poor air conditioning; a fan that runs constantly drains the battery and keeps the engine too cold. Failed fan motors, relays, control modules and corroded connectors are common causes.
On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 17078 (P0694). Both numbers mean the same fault.
Symptoms of P0694
- Engine overheats in traffic or at idle
- Fan runs constantly or not at all
- Air conditioning weak when stationary
- Battery drained (fan running after switch-off for too long)
- Check Engine light on
Most common causes of P0694 (most likely first)
Mechanic's Pro Tip
Look at the fan connector before replacing the motor: a burnt or melted connector shows that the old motor drew too much current. Replace the connector pigtail too, or the new fan will soon fail at the same place.
1.Open circuit in the signal or ground wire
Most likelyA loose ground connection is a very common cause.
2.Signal wire shorted to the 5 V reference or battery voltage
3.Faulty radiator cooling fan
4.Blown fuse or burnt connector
High currents overheat weak connections.
5.Wiring fault
Step-by-step diagnostic guide
- 1
Read codes and command the fan
Read all codes and use the scan tool output test to run the fan at each speed.
- 2
Check signal and ground
With the ignition on and the radiator cooling fan plugged in, back-probe the signal and ground wires. A signal stuck at reference or battery voltage points to an open ground/signal wire or a short to voltage.
Multimeter: Ground wire to battery negative: below about 0.1 V. Signal stuck at about 5 V (or 12 V) = open or short to voltage.
- 3
Check fuses and relays
Check the high-current fan fuses and the relays or control module.
- 4
Check power and ground at the fan
Measure the voltage at the fan connector when it is commanded on and check the ground.
Multimeter: Close to battery voltage at full speed; a large voltage drop indicates poor connections.
- 5
Check the motor
Measure the current draw or spin the fan by hand to feel worn bearings.
- 6
Repair and verify
Replace the faulty part, check that the fan runs at the correct coolant temperature and with the A/C on.
Frequently asked questions
Can I keep driving with P0694?
Only with care. Without a working fan the engine can overheat in traffic – watch the temperature gauge and avoid queues until it is fixed.
How much does it cost to fix P0694?
Typical repair costs are 20 € – 600 €, depending on the cause and the vehicle. The most common fixes are: open circuit in the signal or ground wire; signal wire shorted to the 5 V reference or battery voltage; faulty radiator cooling fan. Always confirm the cause with the tests above before buying parts.
Is it safe to drive with a cooling fan fault?
Only if you keep moving at speed and watch the temperature. In traffic the engine can overheat quickly.
Why does my fan run after I switch off the engine?
Many cars run the fan for a few minutes to cool the engine. If it runs for a long time or drains the battery, the control or relay is faulty.
What is the difference between P0694 and similar codes?
P0694 belongs to a group of codes for the same component that differ in the type or location of the fault: P0529 – Fan Speed Sensor Circuit Intermittent; P0691 – Fan 1 Control Circuit Low; P0692 – Fan 1 Control Circuit High; P0693 – Fan 2 Control Circuit Low; P0695 – Fan 3 Control Circuit Low; P0696 – Fan 3 Control Circuit High. The tests on this page apply to the whole group; the type of fault tells you where to start.
Related fault codes
This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.