Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Ignition voltage is supplied directly to Fan Control (FC) relays No. 1 and 2. PCM controls the relays by grounding the control circuit through an internal solid state device called the driver. The driver supplies the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When PCM is commanding a component on, the control circuit should be low (near zero volts). When PCM is commanding a component off, the control circuit should be high (near battery voltage).
If the fault detection circuit senses a voltage other than what is expected, this DTC will set. This DTC will also set when there is a short to ground, open in circuit, or short to battery voltage is detected on control circuit and when condition is present for at least 30 seconds.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.