How to disable exhaust temp warning light?

soldave · 06-20-2010, 04:55 AM

I think I may have fried or destroyed my exhaust temp sensor somehow soon after fitting my decat yesterday. I'd seen it flicker on before driving to the garage when letting off on low rpms (2-2,500 or so). After fitting the decat and hooking up the sensor again I drove around. After about 20 minutes I saw the exhaust temp sensor start to flicker on and off again and then just came on and stayed on. I pulled over and let the engine cool down and started it up again. Sensor is staying on from the start now, even with a stone cold engine.

Now I don't know if the car is running lean or timing is off and the temperature really was high, although I don't think either are happening. But my exhaust warning light is constantly on now which is a bit of a distraction. Am going to be getting an EGT gauge anyway so is there any way to stop the exhaust/temp warning light from coming on?

Cheers for any advice you can offer me

NoDOHC · 06-27-2010, 08:45 AM

You would have to look at the FSM find the schematic for it. I have never seen that light come on, even when I had white-hot exhaust from running on the dyno at 9,000 rpm with the factory ignition. I know the light exists, but I don't know how the sensor is wired.

soldave · 06-27-2010, 08:48 AM

I worked it out in the end. The temp sensor works as some kind of resistor, and if the voltage drops below 1.5V it triggers the warning. What has happened is that my wiring has just come apart in quite a few places, meaning the voltage going back to the ECU is always going to be under 1.5V and setting off the warning.

06-20-2010, 04:55 AM	#1
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	How to disable exhaust temp warning light? I think I may have fried or destroyed my exhaust temp sensor somehow soon after fitting my decat yesterday. I'd seen it flicker on before driving to the garage when letting off on low rpms (2-2,500 or so). After fitting the decat and hooking up the sensor again I drove around. After about 20 minutes I saw the exhaust temp sensor start to flicker on and off again and then just came on and stayed on. I pulled over and let the engine cool down and started it up again. Sensor is staying on from the start now, even with a stone cold engine. Now I don't know if the car is running lean or timing is off and the temperature really was high, although I don't think either are happening. But my exhaust warning light is constantly on now which is a bit of a distraction. Am going to be getting an EGT gauge anyway so is there any way to stop the exhaust/temp warning light from coming on? Cheers for any advice you can offer me

06-27-2010, 08:45 AM	#2
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	You would have to look at the FSM find the schematic for it. I have never seen that light come on, even when I had white-hot exhaust from running on the dyno at 9,000 rpm with the factory ignition. I know the light exists, but I don't know how the sensor is wired. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

06-27-2010, 08:48 AM	#3
soldave Rotary Fanatic Join Date: Jun 2010 Location: Okinawa, Japan iTrader: (0) Posts: 134 Rep Power: 15	I worked it out in the end. The temp sensor works as some kind of resistor, and if the voltage drops below 1.5V it triggers the warning. What has happened is that my wiring has just come apart in quite a few places, meaning the voltage going back to the ECU is always going to be under 1.5V and setting off the warning.