hey guys, i have a error with my 7mgte when i rewired the car, and that is the hac sensor. Now i live in Holland and the highest road in the country is not even 1000 ft above sea level so a hac sensor is a pretty useless sensor to have over here. Is there any way to rewire the car and eliminate the hac sensor without it trowing a code?
eliminate hac sensor
- Thread starter antigram
- Start date
Sure. Question is, which HAC version do you have? The older ECUs use an external sensor, mounted under the glove box. That one is simple to deal with.
The later ECUs, on the other hand, use a sensor that's on the ECU mainboard. That one is a serious PITA.
I forget what kind of output they provide, but I'd be willing to bet that the ECU reverse engineering thread could likely provide some useful information there. http://www.supramania.com/forums/showthread.php?73379-3P-s-TCCS-Disassembly-Analysis
The later ECUs, on the other hand, use a sensor that's on the ECU mainboard. That one is a serious PITA.
I forget what kind of output they provide, but I'd be willing to bet that the ECU reverse engineering thread could likely provide some useful information there. http://www.supramania.com/forums/showthread.php?73379-3P-s-TCCS-Disassembly-Analysis
A more important question is...why bother deleting it, even if you don't use it? It's hardly an inconvenience to just leave it alone.
Well, What I'm understanding here is that the OP re-wired the car, and now somehow the HAC sensor is not working.
From this, I deduce that the OP HAS a HAC sensor, so it's an '86.5-'88 car. I also deduce that there's a code coming up in the ECU and that it's probably a HAC sensor code, causing the ECU to go into a limp mode all the time (Or just light the CEL), even though there shouldn't be a high altitude to compensate for.
What I'd suggest is that you fix the wiring. It's a couple of short wires to the HAC sensor, and one connector. It shouldn't be THAT much of a problem to figure out what happened to it.
If the ECU is a newer one ('89+ car) then a HAC sensor code means that you did something bad to the ECU and you should replace it. I suppose that's a possibility for the older ECU as well, which I'd confirm by checking/testing the HAC sensor wiring. Really, it's one of the shortest wire runs int he entire car, how hard can it be to troubleshoot?
From this, I deduce that the OP HAS a HAC sensor, so it's an '86.5-'88 car. I also deduce that there's a code coming up in the ECU and that it's probably a HAC sensor code, causing the ECU to go into a limp mode all the time (Or just light the CEL), even though there shouldn't be a high altitude to compensate for.
What I'd suggest is that you fix the wiring. It's a couple of short wires to the HAC sensor, and one connector. It shouldn't be THAT much of a problem to figure out what happened to it.
If the ECU is a newer one ('89+ car) then a HAC sensor code means that you did something bad to the ECU and you should replace it. I suppose that's a possibility for the older ECU as well, which I'd confirm by checking/testing the HAC sensor wiring. Really, it's one of the shortest wire runs int he entire car, how hard can it be to troubleshoot?
Well i wired it up without a HAC sensor, I only have the wires going to the engine loom and the cluster as i bought the car without a dash or any sensors. The car is a pre facelift so it should have an external hac sensor but i only knew of its existence since the ecu is giving this CEL haha. I wanted to buy a hac sensor to fix it but no one in holland seems to have one for sale and as its not gonna be used anyways overhere i can't be bothered to import one from the other side of the world if i can also delete it.
With that error code the default value is near sea level @ standard atmospheric conditions. If the MIL being on bothers you (and assuming you had an external HAC sensor) use whatever resistance is needed to apply appx 3.6 vdc to the HAC terminal. Problem solved...