* Check Engine Light (CEL): This is a broad indicator. It means the onboard diagnostic system (OBD-II) has detected a problem somewhere in the engine's control system or emissions system. This could range from a minor issue like a loose gas cap to a serious problem like a failing catalytic converter or oxygen sensor. You must have the OBD-II codes read using a scan tool to determine the specific problem(s). Auto parts stores often offer this service for free.
* CFC Light (Assuming AC Compressor Clutch): This light indicates a problem with the air conditioning system. Common causes include:
* Low refrigerant: The most frequent cause. AC systems require a specific charge of refrigerant; a leak can cause the system to underperform or fail entirely.
* Compressor clutch malfunction: The clutch engages and disengages the compressor. A faulty clutch could prevent the compressor from working.
* Electrical problems: Issues with the wiring, fuses, or relay related to the AC compressor.
* Pressure switch problems: A faulty pressure switch may prevent the compressor from engaging.
The Connection: While seemingly unrelated, there's a *slim* chance of a connection between the two lights. For example:
* Electrical issue: A shared electrical component could be causing problems in both the engine and AC systems.
* Parasitic drain: A significant electrical drain (perhaps a faulty alternator) could affect both systems. This is less likely to cause the CFC light, but possible.
What to do:
1. Read the OBD-II codes: This is the most crucial step. Get the codes read to identify the specific engine problem.
2. Check the AC system: If the CFC light is solely related to the AC, you might start by checking the refrigerant level (this requires special equipment and knowledge or a professional). If the refrigerant level is low, you'll need to find and repair the leak.
3. Professional diagnosis: If you're unsure about any aspect of the diagnosis or repair, take your 4Runner to a qualified mechanic. Trying to fix issues based on assumptions could lead to further damage or unexpected costs.
Don't ignore these lights. Driving with a malfunctioning engine system can damage components, and a failing AC system can cause discomfort or even safety issues (reduced visibility in hot climates).
