firebirdjones

My problem is simple really once I explain what I am doing. I have an 88 Iroc, cruise control is inoperative. I also have the GM service manual, in the diagnostic procedure it starts by telling me to remove the connector on the cruise control module and test some of the pins (J, K, etc..) no problem this is easy to do only there is one problem. I cannot locate the cruise control module.
The GM book says it is in one of two places, either it is bolted to the pedal assembly or it is integral with the ECM.
Anyone familiar with this? I have looked on the pedal assembly and see nothing resembling a module, only the vacuum control switch for the cruise. I look at the ECM under the passenger side dash and thats just it, thats all I see, with one big plug in connector. Where exactly is this cruise control module so I can unplug it and begin diagnosing this thing? Please don't tell me it is all part of the ECM, I really hate to hear that I am really hoping the cruise has it's own seperate module somewhere and I am just missing it. Please help, thanks in advance, Larry.

firebirdjones

Just to move this to the top, hoping to find someone with experience on this. Just want to make sure where the cruise control module is or what it may look like as the GM manual does not have a clear picture and is vague in it's location. I just want to continue diagnostics correctly. It mentions the cruise control module possibly being integrated into the ECM, in which case does this mean I need to pull the ECM and remove the large plug to look for the terminals I need to test? If this is the case and I find the module defective per the test, would that mean I would have to replace the entire ECM? Boy I hope that is not the case, I am hoping for a little clearification on this before I start ripping out kick panels and stuff for nothing. Thanks for any help guys, you have been great on here so far, Larry.

MikeS

Don't know this firsthand, but it is information that I'll be looking to use in the near future, so I dug up a little thread...

https://www.thirdgen.org/techbb2/sho...cruise+control

I have seen the module back there that he's talking about, but didn't know what it was at the time...

What is the recommended troubleshooting procedure, by the way?

firebirdjones

Hey Mike, thanks for the response, that thread helps a little but I am not sure what the guy is referring to when he mentions the "map pocket" If I knew the area he was talking about I could begin to look for this elusive cruise control module so I can begin diagnostics.
As far as the procedure goes, out of the GM manual, I am heading out the door right now, I can scan it and E-mail you a copy of the pages or try to describe it here. It basically starts off by locating the cruise control module, pulling the plug, and then testing the terminals inside the plug, it then leads you to several other tests depending on how the terminals test inside the plug, it then narrows the problem down step by step, pretty easy to follow if I could just find the cruise control module I will check back here later today when I get back, let me know if you need some copies of the diagnostic pages, Larry.

tom3

On my 88 the module is in the dash, passenger side up near the top sort of beside the ECM. Take the dash top off and look down and you'll see it. Kind of sandwiched in between some ducts or something. Hard to get to. About the size of a pack of cigarettes, somewhat larger I guess. Guess this would be in the area of the map pocket on a Firebird dash?

firebirdjones

Ah Ha, thanks a million, that was what I was hoping to here. I will check that out, and hopefully fine mine in there. Thanks Tom, I wish the GM manual was a little more clear on that or at least give me a good picture of it so I know what I am looking for. Oh well, I knew someone on here would lead me in the right direction. Thanks again Larry.

firebirdjones

Hey Tom, thanks again, as it turns out, the module is in the exact place you mentioned. I crawled under the passenger side dash with a light and sure enough there was a black box just as described hiding up in there. I was able to remove it from the bottom without taking out the dash pad. I removed 3 screws and it was laying in the floor in a couple minutes.
I was able to test the terminal plug and run through diagnostics and it turns out that the multi function turn signal switch is bad. Pretty simple fix once I could diagnose this thing properly. Called GM yesterday to order the switch, comes in today, $82.00, a little more than I thought but oh well. Thanks for the help, this board has been great, Larry.

jconrad

I would just love to get my hands on a copy of that diagnostic procedure...mine is not working, but the switch reads okay.