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.
Code C: Sunlight Sensor
2004 Acura 3.5RLSECTION Code C: Sunlight Sensor
- Remove climate control unit and disconnect 8-pin and 20-pin harness connectors. See CLIMATE CONTROL UNIT under REMOVAL & INSTALLATION. Remove sunlight sensor and disconnect harness connector. See SUNLIGHT SENSOR under REMOVAL & INSTALLATION. Check for continuity between ground and terminal No. 16 (White/Red wire) of climate control unit 20-pin harness connector. If continuity exists, repair shorted White/Red wire between climate control unit and terminal No. 2 of sunlight sensor. If continuity does not exist, go to next step.
- Check for continuity in White/Red wire between terminal No. 16 of climate control unit harness connector and terminal No. 2 of sunlight sensor harness connector. If continuity exists, go to next step. If continuity does not exist, repair open in White/Red wire.
- Check for continuity in Pink/Blue wire between terminal No. 2 of climate control unit 8-pin harness connector and terminal No. 1 of sunlight sensor harness connector. If continuity exists, go to next step. If continuity does not exist, repair open in Pink/Blue wire.
- Reconnect sunlight sensor harness connector. Test sunlight sensor. See SUNLIGHT SENSOR under COMPONENT TESTS. If sunlight sensor is okay, check for loose wires or poor connections at climate control unit 8-pin and 20-pin harness connectors and sunlight sensor harness connector. If connections are okay, substitute known-good climate control unit and recheck. If symptom does not exist after substituting known-good climate control unit, replace original climate control unit. See CLIMATE CONTROL UNIT under REMOVAL & INSTALLATION.
RENDER: 1.0x
NO RELATED
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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.