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Ask A. Penland Your Own Question
A. Penland
A. Penland, Ford Senior Master Technician, ASE
Category: Lincoln
Satisfied Customers: 6216
Experience:  ASE Master Certified. ASE Gasoline Engine Performance Certified,Ford Senior Master Technician
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I have a 2004 Lincoln Navigator with 220,000 mile on it.

Customer Question

I have a 2004 Lincoln Navigator with 220,000 mile on it. Recently I had to replace the left rear hub and ABS sensor. About a month after I did that I got a C1998 code and had the "slippery car" thing flashing on my dash. I took it in and they reset the ABS module and everything went away.
Then I realized, about a month after that, that I can't switch into 4WD. The light doesn't come on. Also, and maybe unrelated, I occasionally get a whining sound coming from the front LHS under the hood like a "whistle".
Yesterday we got a lot of snow and I was driving around. I couldn't get into 4WD as it didn't work. When I got to a hill I couldn't make it up the hill. The engine just bogged down and wouldn't give me any power to the wheels. I put it in neutral and revved the engine and it worked fine. I put it in the lower gears and nothing helped. As soon as I got into a low traction scenario the engine bogged down. FYI, maybe not related, I found I could put the transmission into reverse even when going forward (found it by mistake).
I can't get the wheels to get power from the engine now if the wheels get into any low traction scenario. The Nav is sitting at the end of my driveway right now as I couldn't get it up the small hill. Any thoughts as to cause?
Submitted: 9 months ago.
Category: Lincoln
Expert:  roybelding replied 9 months ago.

good morning my name is ***** ***** I will assist

does the transmission seem like it is working through the gears???

if it is, it sounds like you may have a clogged cat converter not allowing the engine to breathe.

I also question the abs codes. codes come up for a reason. re setting the module does nothing for the issue. the code needs to be looked at to determine why it set. I hate it when people re set the code as it never accomplishes anything. that code could effect traction control as well. it wont effect the*****but will effect other systems..

Roy

Customer: replied 9 months ago.
I can go test it now. If the pavement is dry it works absolutely perfectly. The only time this shows up is when there is low traction like the big snow dump we just got and/or trying to go up a hill with a little bit of snow. The transmission seems to shift well though. I checked the transmission fluid and had to move the selector through the gears. It does "clunk" when going into gear but it has done that since I got it. I can't tell if that's abnormal or not.I took the car into a garage for the ABS thing and all I noticed was the traction light thing wasn't on anymore. I can't correlate the loss of 4WD to that event or if it wasn't working previously. We've had a pretty mild winter and I hadn't tried 4WD until recently and after I had the ABS looked at.Any obvious way to check for a clogged cat converter?
Expert:  roybelding replied 9 months ago.

no obvious way. you need a back pressure gauge to test back pressure.

Roy

Expert:  roybelding replied 9 months ago.

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Customer: replied 9 months ago.
Apologies, had to drop off yesterday. So the gears and power seem to work fine yesterday when the snow melted. It only seems to "bog down" and get no power when the wheels can't get traction. I don't understand how the catalytic converter being plugged would make the engine not run well and the transmission not get power to the tires. The instant I take the lincoln out of any gear when I have it under load and put it into neutral and then stomp on the gas the motor runs fine. The instant I put it back into gear when the back tires can't get traction the motor bogs down.
Expert:  roybelding replied 9 months ago.

ok, the fact that it only happens when the wheels are spinning tells me the trac control took over and will not allow you to rev the motor as it will continue with wheels spinning. that is the trac control trying to get traction for you to move.

Roy

Customer: replied 9 months ago.
That's what I think it is but I don't know how to troubleshoot. Can I turn the traction control off somehow and see if it happens? I did a quick read and it seems this could be a failure of a speed sensor on a wheel. Any thoughts on how to narrow it down?
Expert:  roybelding replied 9 months ago.

its not a failure. it is working the way it was designed.

there is a switch to turn it off. look in the rear on either side for a switch. it may be in a compartment on the sides

Roy

Customer: replied 9 months ago.
i know there is an air ride suspension switch on the inside on the left hand side. I will check as I think there may be a switch right on the dash that turns it off.
Expert:  roybelding replied 9 months ago.

ford puts them all over the place.

Roy

Expert:  roybelding replied 9 months ago.

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Customer: replied 9 months ago.
went for a spin in the Nav. The button is on the dash. I tried to drive on the side of the road so that either my left side or right side tires were in the snow/slush and then turned the traction control on and off. I think, but am not 100%, that the motor didn't bog down as much with the control off. If it is the traction control taking over and bogging down the motor what is the remedy for the cause?
Expert:  roybelding replied 9 months ago.

once again, the trac will control the motor so you dont continue to spin. it is trying to control the truck to get you moving and not allow wheel spin. the system is working correctly

Roy

Customer: replied 9 months ago.
Something has got to be wrong. I was on a 30 degree slope and I couldn't get power to the back wheels. I also can't get the 4WD to turn on at all. I had every other car going by me and had to back down to take a run at the slope to get over it. I've driven the Nav a lot of places and never had it do this. It's not normal.
Expert:  A. Penland replied 9 months ago.

Have you been able to take it to any repair shop to have all the modules in the vehicle tested for trouble codes?

Customer: replied 9 months ago.
I had to take it in to a garage. I have a code reader and it gave C1998. When I took it to the garage it was cleared. I just had C1998 a couple of days ago when I had the traction problem. I cleared it again and checked it last night to see if it came back. it had not (but i will check again today).
Expert:  A. Penland replied 9 months ago.

The code C1998 is for a module configuration error with the ABS module. Either the module is internally faulted or it needs to be properly programed and then have the vehicle driven and retested to see if the code C1998 returns.

Customer: replied 9 months ago.
Hi, I had taken the Nav into the garage to solve the blinking traction control light. They reprogrammed the ABS module and all seemed fine. Did you see the explanation I gave to the previous person? It has all the details.I have a 2004 Lincoln Navigator with 220,000 mile on it. Recently I had to replace the left rear hub and ABS sensor. About a month after I did that I got a C1998 code and had the "slippery car" thing flashing on my dash. I took it in and they reset the ABS module and everything went away. I will go see if the C1998 code is back but here's the original message:Then I realized, about a month after that, that I can't switch into 4WD. The light doesn't come on. Also, and maybe unrelated, I occasionally get a whining sound coming from the front LHS under the hood like a "whistle".Yesterday we got a lot of snow and I was driving around. I couldn't get into 4WD as it didn't work. When I got to a hill I couldn't make it up the hill. The engine just bogged down and wouldn't give me any power to the wheels. I put it in neutral and revved the engine and it worked fine. I put it in the lower gears and nothing helped. As soon as I got into a low traction scenario the engine bogged down. FYI, maybe not related, I found I could put the transmission into reverse even when going forward (found it by mistake).I can't get the wheels to get power from the engine now if the wheels get into any low traction scenario. The Nav is sitting at the end of my driveway right now as I couldn't get it up the small hill. Any thoughts as to cause?
Expert:  A. Penland replied 9 months ago.

And as I stated, see below please.