P0691

Fan 1 Control Circuit Low

Car Fault Codes Cooling & lubrication

Can you still drive? With care, short trips only

Who can fix it? Needs a workshop

Typical repair time 15 minutes – 2 hours

Typical cost SAR 50 to 1,500

What it means

The engine computer (ECU) controls cooling fan 1 through a relay or a dedicated fan control module. The computer detected lower than expected voltage on this control circuit, so the fan may not run when needed or may run constantly depending on circuit design; which fan is called fan 1 varies by manufacturer.

Symptoms4

Engine temperature rising at idle or in traffic.
Weak A/C cooling while stopped.
Fan running constantly even with a cold engine on some vehicles.
Check engine light on.

Possible causes5

Control circuit wire shorted to the body or ground.
Internally damaged fan relay coil.
Faulty fan control module on vehicles that have one.
Moisture or corrosion in fan or relay connectors, an area exposed to water and heat.
Faulty control circuit inside the engine computer (rare).

How to diagnose5

Watch engine temperature and fan operation at idle and with the A/C on.
Use the scan tool to command the fan on if the function is available, and watch its response.
Swap in an identical known-good fan relay to test.
Test the control wire's isolation from ground with both ends disconnected.
Inspect the fan and fan module connectors for melting or corrosion.

How to fix5

Replace the fan relay if its coil is damaged.
Repair the wire shorted to ground and re-insulate and secure it.
Clean corroded connectors or replace melted ones.
Replace the fan control module or fan motor if proven faulty.
Clear the codes and confirm the fan runs when needed, engine temperature is stable and the code does not return.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a relay or wire repair, and rises if a fan control module or new fan motor is needed.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Can I drive with this code?

With caution while watching the temperature gauge, especially in traffic and hot weather. If the temperature rises, stop and switch off the engine, because overheating can damage it.

The fan runs all the time. Is that because of this code?

It can be on some designs, where the computer runs the fan as a failsafe when it detects a fault in the fan circuit, to protect the engine from overheating.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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