Cruise Control Module Interchange

[Turbo6inKY]

My Cruise Control module went out on me, and I was surprised to find not only is the part NLA, but there's very little information anywhere on it, even though the exact same Cruise Control system was used on millions of GM vehicles between 1978 and ~1993. There should be plenty of these things out there.

So I went diving in the junkyard.

The cruise module in my 1987 Grand National bears the GM part number 25074740 with a 37CF part extension. Inside the box is a circuit board with the part number 25074637C.

In a 1988 Pontiac B-Body station wagon, I found a cruise module with the number 25074710 with a 37BH extension, but inside was the exact same 25074637C circuit board.

I also found a 25110868 37FA in a van. Circuit board has the part number 25110819C, and it has a different layout than the GN's board, but it has the EXACT same ICs on it and the same pinout on the edge connector.

I also found a lot of late 1980s front wheel drive models that appeared to have the same servo as our, but I couldn't find the cruise modules under the dash.

 

[GNRick]

How do you know yours is bad?

 

[RmvBfrFlght]

The reason there are so many different cruise modules is the calibration. Different vehicles and drive-trains react differently to throttle input. These calibration differences can be as little as using different resistors and/or capacitors. To change the rate at which throttle changes are made.

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