The AC 138 code itself relates to a problem within the climate control system's circuitry or components. Clearing the code without fixing the root cause will likely result in the code reappearing. You need to diagnose and repair the actual malfunction.
Therefore, instead of focusing on a "reset," concentrate on these steps:
1. Identify the AC 138 code meaning: Look up the specific meaning of AC 138 for your Buick's system. A repair manual (Haynes or Chilton) or an online automotive database will provide this information. The code likely points to a specific sensor, actuator, or wiring issue.
2. Diagnose the problem: Use a multimeter to check the wiring, connectors, and components indicated by the code's definition. Look for shorts, open circuits, or faulty components (like sensors or actuators).
3. Repair the problem: Once the faulty component or wiring is identified, repair or replace it.
4. Recheck the code: After making the repair, clear the code again using your diagnostic tool. If the underlying problem is fixed, the code shouldn't reappear. If it does, there's still a problem that needs further investigation.
In short: Clearing the code is just one small step in troubleshooting. The real work is in finding and fixing the actual mechanical or electrical issue causing the code in the first place. A reset isn't involved.
