1999 Lincoln Town Car Check Trac & Stalling

MRSLICKT

MEMBER
1999 LINCOLN TOWN CAR
4.6L
V8
RWD
AUTOMATIC
155,000 MILES

After a panic stop a couple weeks ago, the Check Trac light started coming on. It is always accompanied by the temp indicator ceasing to work, it always happens on bumpy roads (or sometimes even just on the expansion joints of a bridge).
Also, after the panic stop, I started experiencing a stalling problem any time I hit the brakes with any force. A nice, slow stop isn't a problem but if I have to slow down or stop even slightly more urgently than "average" it stalls. This occurs whether the check trac light is on or off.
I have cleaned and checked the wheel speed sensors, had the suspension rebuilt front to back, had the dealership scan the codes and all they could tell me is "network errors." The FLM dealership couldn't figure out the issue, nor could three other mechanics, nor could the tire / alignment / brake shop.
Any other ideas? I've spent $2000 throwing parts and labor at this car, in addition to my own elbow grease!

8 Replies

HMAC300

MECHANIC
48,601 POSTS

I've been trying to keep away from this one but to me if it only does it on bumps sounds like a body ground is loose someplace. I've had this happen a few; times but it's been a very long time. However it may not fix it but worth a try as that is what it sounds like to me. For the stalling clean both sides of throttle plate and iac hole with choke cleaner. See pics for where grounds are and look at them all because it could be just loose or rusted away. Kick panels are where your feet are by the sides in car. However this may not fix it either as this is hard to diagnose over the computer.

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Monday, July 20th, 2015 AT 9:42 AM

MRSLICKT

MEMBER
3 POSTS

Thanks for answering.
We are stumped. Thanks for the diagrams - we have gone through this and checked every connector from the transmission forward to the front of the car. All the grounds are good, the only thing we found is a connector behind the emergency brake pedal, sandwiched between two similar connectors and leading to the same bundle of wires (through the firewall), which is not connected to anything- nor does there appear to be anything present in order to connect. Confusing.
Anyway, after wiggling and jiggling literally EVERY connector and checking every connection attempting and failing to trigger a dummy light, we rolled the car forward at 2MPH and hit the brakes. "Check Trac" lit up and engine bogged - did it again while "check trac" was still on and engine stalled.
I took some photos of the errant disconnected connector but I'm not sure it's helpful. I'd be glad to attach if you think they'll be helpful.

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Wednesday, July 22nd, 2015 AT 10:13 PM

HMAC300

MECHANIC
48,601 POSTS

I have no idea what to tell you then unless you have harness chafed someplace. That is the only thing I can think of off hand. There are no tsb's for this problem either. It may be where the harness lies on metal and has chafed due to age. If you would like your donation back contact me and i'll see to it.

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Thursday, July 23rd, 2015 AT 5:38 AM

MRSLICKT

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3 POSTS

Thanks. I appreciate the diagrams you attached for us and the help you did provide. I know I'm in deep doodoo when even the local Ford/Lincoln dealership can't figure it out.

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Thursday, July 23rd, 2015 AT 1:27 PM

JASON IBBY

MEMBER
4 POSTS

Hello I had a customer bring his car in after hitting a deer at 80 mph. It’s a 2000 town car executive series 4.6 after replacing body panels and other compromised components I ran it down the road and had the check trac light pop up it down shifted and eventually stalled out of me. After further inspection I found the abs module had failed after he did a hard brake to try and avoid the deer. Idk what exactly happened to the module but after installing a new abs/atc the problem stopped occurring. Hope this helps.