Temp sensor wiring
Temp sensor wiring I just installed the harness and computer for a 2002 Escalade LQ9. I got a 118 code ( engine coolant temp hi) when I turned the key on.
The circuit with yellow wire on the coolant sensor was good to the pin 74 on the computer. However the grey wire on the coolant temp sensor was cut. The diagram shows this is supposed to be connected to pin 41 of the computer. There'a also no pin in the computer connector for pin 41, I assume it was removed by the guy who did my harness.
This terminal is labeled as ground on the computer and also grounds the automatic transmission TFT sensor (I'm not using the auto trans, I've got a Richmond 6 speed instead).So my question is do I need to run a ground from the grey wire on the temp sensor to pin 41 of the computer, or will an engine block ground work?
The circuit with yellow wire on the coolant sensor was good to the pin 74 on the computer. However the grey wire on the coolant temp sensor was cut. The diagram shows this is supposed to be connected to pin 41 of the computer. There'a also no pin in the computer connector for pin 41, I assume it was removed by the guy who did my harness.
This terminal is labeled as ground on the computer and also grounds the automatic transmission TFT sensor (I'm not using the auto trans, I've got a Richmond 6 speed instead).So my question is do I need to run a ground from the grey wire on the temp sensor to pin 41 of the computer, or will an engine block ground work?
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
Yep, just run the ground all the way back to the PCM, you will kick yourself later if you don`t. The PCM`s are very sensitive to grounding of sensors, if you ground it to the engine you might end up with intermittent codes of the PCM thinking the temp is off.
