2003 Lincoln Navigator c1991

Adrean Diagnostician Bakersfield, California Posted   Latest  

goodmorning Everyone. I am working on this 2003 Lincoln Navigator , the truck has electronic suspension. And it had code c1991 and c1725 .. I checked it out and found the rf air shock was leaking due to the oring on the solenoid not being installed , so i Install the oring and no more leaks . Car now airs up the front . But the check suspension message will come up with code c1991 .. I tried with autel and snap on to relearn the height calibration , But I’m having trouble completing this and clearing the code . Any one that has successfully done this with snapon or autel or do I need a ngs or ids ? Thanks in advance 

Robert Mobile Technician
Newark, Delaware

Does your scan tool have the option run the trim set function and a Pneumatic test? I I have had this very issue before where you fix the problem but the message and code won't go away. I want to say that after you run the pneumatic test you you should be able to clear the code. I've never tried using anything but ids on them.

+1 Ð Bounty Awarded
Martin Instructor
Burnaby, British Columbia

Adrean, since the "O" ring was not installed, there must be an underlying reason. Although I have zero experience with the vehicle, I'd wonder if perhaps an aftermarket solenoid has been installed of dubious quality. Possibly IDS will be needed to complete a re-calibration of the height sensor. "Googling" might just yield some useful information, because it seems that this is not an isolated issue. Of course, take such information with a "grain of salt" at face value.

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Adrean Diagnostician
Bakersfield, California

They had replaced the front air shock . And they didn’t installed the new oring . Just had a hard time doing the procedure it shows on google but I will try again 

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Glen Technician
Arthur, Illinois

Did you already read TSB 03-13-02 ?

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Chris Technical Support Specialist
Commack, New York

That tsb is a good source for general information on this system.

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Chris Technical Support Specialist
Commack, New York

The ride height calibration should be able to be set with FJDS. You can use a J2534 Pass through such as the Cardaq Plus2 for this function. If you can not raise and lower the suspension with active commands on a scan tool, it will not pass the test. I have found that sometimes if the raise/lower time is too long (weak compressor or clogged vent) it will not pass.

I had also had the chance to work with a local shop on one of these not too long ago. The had made several repairs to this vehicle. Each time they would test the system the bags would inflate until they popped. They had replaced the bags and had tried again, it would keep raising up, they would pull the fuse and lower it with the scan tool. Turns out that they had swapped the sensors in the rear from left to right. When the compressor was on the system would raise, but the module saw the height sensors lowering and would leave the compressor on! They had swapped the sensors back and resolved the issue. Simple mistake that cost the shop a lot of time and money.

+1 Ð Bounty Awarded
Jason Instructor
Nanticoke, Pennsylvania

It may sound simple and stupid but I had a 2003 Navigator one time that would not relearn trim heights and would not complete calibration and clear the codes after the repair on a sensor was completed. It turns out there was nothing wrong with the vehicle it was more so my process of calibration. First thing was my snap on modis did an auto detection for the vehicle and populated it as a 2004 somehow when in fact it was a 2003. So definitely verify proper year. Second was i plugged into the OBD connector and stood next to the vehicle with the door open. I must have been in a hurry and didn't properly read the process where it said to close all doors. Once I closed the door and ran the scan tool cable through the window the calibration learned successfully. 

I guess the moral of the story is, Read and verify all data that comes up on the scan tool screens. Don't just click though it all in a rush. Read the details and a complicated problem may turn out to be something simple.

+2 Ð Bounty Awarded