Powertrain, generic · Computer and auxiliary outputs
P0694 Fan 2 Control Circuit High
Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo
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. 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. P0694 means the fan 2 control circuit is shorted to voltage; Ford's 2023 diesel checks its auxiliary fan relay within 0.5 s.
Likely causes
Control wire shorted to battery or ignition voltage
Relay coil open or wrong relay fitted
PWM fan module feeding voltage back onto the control line
Engine module driver faulty
Symptoms
- Check engine light (GM after two trips)
- Fan does not run
- Rising coolant temperature in traffic or with A/C on
- A/C may be switched off to protect the engine
Repair estimate
DifficultyEasyDIY possible
Parts and labour€20–400
Time0.3–2 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
cooling fan relayfan control circuitengine control module
Related codes
References: law.cornell.edu, gsi.ext.gm.com, fordservicecontent.com, saabwisonline.com.