04 LS Abs, Trac lights, engine failsafe help

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VividLSE

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A few days ago, the abs light came on shortly followed by trac light and the message center telling me to check both. The engine now also now goes into failsafe mode. I have noticed that the spedo now flux from true speed to slower than true. I had codes pulled and i have a list! Both rear speed sensors, right front speed sensor, comm's error, etc... I know these things didn't go bad all at the same time. Anybody have this happen or know what would cause all these things to go almost at once?:confused:
 
Full list of code?
Which failsafe mode? Engine cooling failsafe or ETC (electronic throttle control) failsafe?
If the latter, when's the last time all the coils and plugs were replaced?

For the rest of it, check the wiring harness near the ABS module.
 
ETC failsafe. I left the full list of codes at work. Plugs about 18 months ago after dealer replaced two coils under warranty. The abs light is on from key on, trac light takes awhile. ETC mode is hit or miss. Drove it three times after work, first drive ETC mode, second no ETC, third was back on.
 
"Random" ETC failsafe is most often triggered by a marginal COP (coil).
 
I know about the COP issues. Have been down that road! I have noticed that it goes into etc when the trac light and check message comes on. I've also had a "check trans" message thrown in there for good measure.
 
VividLSE said:
I know about the COP issues. Have been down that road! I have noticed that it goes into etc when the trac light and check message comes on. I've also had a "check trans" message thrown in there for good measure.
Click to expand...

Loss of vehicle speed data will cause one of the ETC failsafe modes, but it should still give you full engine power. You probably have a harness problem or an ABS module problem. Troubleshooting is pretty straight forward.
http://deneau.info/ls/s6x~us~en~file=s6x69003.htm~gen~ref.htm
 
Thanks so far. An update, i have checked the speed sensors with ohm meter and all seem to be OK. Did this at the wheels and at the abs mod. I get an abs light from the time i key on the car. As you start driving, the speedo reads about half speed, as you build speed, the speedo jumps to correct speed and the traction light turns on with "check trac control" in the message center? I do have full power unless you jump on it or spin tire, then it seems to go into ETC mode...
 
VividLSE said:
Thanks so far. An update, i have checked the speed sensors with ohm meter and all seem to be OK. Did this at the wheels and at the abs mod. I get an abs light from the time i key on the car. As you start driving, the speedo reads about half speed, as you build speed, the speedo jumps to correct speed and the traction light turns on with "check trac control" in the message center? I do have full power unless you jump on it or spin tire, then it seems to go into ETC mode...
Click to expand...
i suggest a lincoln/ford dealer diagnostic check...
 
Ok the codes are! From the abs module C1236, c1235, c1155, u1262. Engine codes p0500, p1000, p2106, u1039. I know what the codes are, just don't know what is causing them! HELP
 
VividLSE said:
Ok the codes are! From the abs module C1236, c1235, c1155, u1262. Engine codes p0500, p1000, p2106, u1039. I know what the codes are, just don't know what is causing them! HELP
Click to expand...

I'm sticking with "For the rest of it, check the wiring harness near the ABS module." Like I suggested before. These codes support this as a possible cause. Have you done this? Have you traced it from the ABS module to the wheel speed sensors? I don't see speculating anymore about this until you've done this. (Check it visually and with an ohm-meter.)
 
Thanks joegr, I have, see post #7. Measured at the wheel and at the abs mod. Even placed a dummy load resister in at each tire location and measured at the abs module. All the wiring around the car looks very good, i unplugged and replugged every connection, just don't know. With the few "missing speed signal" codes, i'm thinking it has to be the abs module...
 
Update, it turns out that it was a bad rear speed sensor. Even though it past the multimeter test, it wasn't putting out a good signal. Used a Snap on Solus to find that. New sensor on, and all is good!
 
A good scan tool is invaluable in tracking down problem with modern cars!
 
Thanks for closing this out with the resolution. It helps others down the road.
 
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