I just found out that the HAC code is called a High Altitude Compensator sensor to detect atmospheric (absolute) pressure "If the ecu records diagnostic code 35 it goes to fail safe and the atmospheric pressure is set at 760mm Hg. This HAC sensor is built into the ecu".

Yamene probably knows about this capacitor but I do not and hoping Yamene or anyone else could advise me about his problem before I send my ECU to another service repair shop in MA.

Thanks for any information you can tell me about this code and this sensor signal and if it may be another part that needs to be replaced as opposed to the ECU.

In my previous post this afternoon about this, I also said that the other Code is 47 which is the sub-throttle position sensor signal and I was going to purchase a new one of these. Hopefully, I could replace the Sub TPS and the ECU and it would solve the problem, start up and run smoothly

Tyndale Cobb

 

Puredrifter and all, I believe that your link is telling me that Code 35 (HAC) sensor signal, is not related to the ECU, but is a problem with my AFM? Thanks for the help and response.

If it is the AFM, is there a means of testing the AFM for that error code or problems? Would the AFM cause my car to buck and stop after approx. 5 minutes once I have started it? I replaced the sub-throttle position sensor and the Code 47 went away, but then got a new Code 28 this morning, which is the upstream right bank O2 Sensor.

Could a faulty O2 Sensor bring the car to bucking and stopping after approximately 5 minutes of running?

Thanks for any help and advice, Tyndale Cobb