What Does P0693 Mean?
The PCM has detected that the control circuit for cooling fan 2 is reading lower than expected voltage. This indicates a short to ground, an open circuit, or a failed fan relay/driver in the secondary cooling fan circuit. The driver may notice the engine running hotter than normal, especially at idle or low speeds, and the A/C system may not cool effectively.
Common Causes
30%
Failed cooling fan 2 relay or control module with internal short to ground
25%
Short to ground in the wiring harness between PCM and fan 2 relay/motor
20%
Cooling fan 2 motor with shorted windings drawing excessive current
15%
Failed PCM fan control driver circuit (internal PCM fault)
10%
Corroded or damaged connector at fan relay or fan motor causing resistance path to ground
Diagnostic Steps
1
Monitor fan 2 control circuit voltage with a DVOM at the relay control terminal; with key on engine off, command fan 2 on via scan tool and verify voltage drops below 1V (normal) vs staying low continuously (fault).
2
Disconnect the fan 2 relay and measure resistance from the PCM control wire to ground; reading below 5 ohms indicates a short to ground in the harness.
3
Inspect the fan 2 relay connector and fan motor connector for corrosion, burned terminals, or water intrusion; pay special attention to harness routing near exhaust components.
4
With the relay removed, apply 12V directly to the fan motor terminals to verify the motor spins freely and draws less than 20A; excessive current draw indicates a shorted motor.
5
If wiring and relay test good, monitor the PCM output driver with an oscilloscope; a flat-line low signal with relay disconnected points to an internal PCM driver failure.
Estimated Repair Cost
$50 - $450
Parts + labor, varies by vehicle and location
The PCM has detected that the control circuit for cooling fan 2 is reading lower than expected voltage. This indicates a short to ground, an open circuit, or a failed fan relay/driver in the secondary cooling fan circuit. The driver may notice the engine running hotter than normal, especially at idl...
The most common cause of P0693 (Fan 2 Control Circuit Low) is: Failed cooling fan 2 relay or control module with internal short to ground
Typical repair costs for P0693 range from $50 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Driving is possible for short distances at highway speeds where ram air provides cooling, but extended idling or city driving risks engine overheating. If the temperature gauge rises above normal, pull over immediately to prevent head gasket or engine damage.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0693 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Cooling System
Difficulty
Type
Generic (SAE)
Recommended Tools
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