92 cruise control inop
Thread Starter
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
92 cruise control inop
Does anyone have a checklist or way to find out why my cruise control quit? It won't engage. I found the cruise control module sitting above the CDM in my FSM. I hope I don't have to remove the CDM again. What usually fails in the cruise control system?
Team Owner
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
In the FSM the diagnostics following the wiring diagram should do well. 8A-34-3 for diagnostics. Wiring @ 8A-34-0
Advanced
Joined: Jul 2017
Posts: 93
Likes: 18
From: Texas
Easiest check is to look at the vacuum hose that goes from the cruise control servo (above the battery) to the brake pedal switch (it goes through the firewall). It is likely dry rotted and can't hold a vacuum anymore. The same issue could happen with the diaphragm of the servo, which is more expensive and has a bit of set up with a new servo.
If the hose is the problem, it's a half hour fix tops.
Take a piece of the hose to a parts shop, get about a yard of hose and some silicone grease so you can slide it through the nipple in the firewall. I think you have to take the cover below the steering column off to get at the switch, and do a bit of contorting since you're under the dash.
Be VERY gentle with the brake pedal switch, I actually slit the hose so it would be easy to pull off.
If this is not the issue, you'll need to use the FSM. The electronics are typically reliable, I'd suspect the hose or the diaphragm of the servo.
If the hose is the problem, it's a half hour fix tops.
Take a piece of the hose to a parts shop, get about a yard of hose and some silicone grease so you can slide it through the nipple in the firewall. I think you have to take the cover below the steering column off to get at the switch, and do a bit of contorting since you're under the dash.
Be VERY gentle with the brake pedal switch, I actually slit the hose so it would be easy to pull off.
If this is not the issue, you'll need to use the FSM. The electronics are typically reliable, I'd suspect the hose or the diaphragm of the servo.
Pro
Joined: Mar 2007
Posts: 596
Likes: 355
From: Mt Prospect IL
2025 C4 of the Year Finalist - Unmodified
My vacuum line melted from batter acid right where it goes by the battery. I took a piece of rubber vacuum hose that fit tight over the plastic vacuum line and spliced it at the failed point.
Team Owner
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
None of you (#3, 4, 5 or 6) mentioned checking the 'damn fuse' - the OP didn't mention anything except don't engage! That's why I pointed him direction of FSM!
#1 - check FUSE
vacuum is NEXT!!!!
#1 - check FUSE
vacuum is NEXT!!!!
Last edited by WVZR-1; Nov 11, 2021 at 09:46 AM.
