I just acquired a

2004 Jaguar X-Type (manufacture date 03/2004)
3.0 Liter
84K Miles

I have the following dashboard Indications
ABS Light
MIL Light
Airbag Light
"Gearbox Fault" message

I checked the DTC codes and I have two
P1637 - which indicates CAN issue between ECM and ABSCM
P1000 - which indicates the status tests are not complete (hence I can ignore this DTC)

I checked/cleaned the 4 wheel sensors
I reseated the connections at the ECM, TCM and ABSCM
I reseated and scraped the ground connection at the battery where it connects to frame.
I disconnected the battery for a few hours
I cleared the codes and they come back immediately (without even starting the vehicle)

Where do I go from here? This particular DTC doesnt really point me in any direction except possible ECM or ABSCM failures. Those are obviously very expensive items to replace and I would rather not just guess at the problem.

Does anyone have a diagnostic path to recommend. I assume there is a diagnostic process the factory would use. How can I test the ECM or ABSCM?

Can a bad wheel speed sensor cause this issue? I do have a cracked brake light switch on the brake pedal......but its still functional via duct tape. (I have the part on order)

Any help would be greatly appreciated.

Thanks

 

GMC, first off, welcome to the Forums. Lots of good information here and lots of very friendly people too. But, we do ask a small favor from you. We pride ourselves in being a better car group and as part of this, we like to get to know one another. So, please stop by the New Member Section and give us a little tidbit about yourself and why you got a Jag and this will give you a chance to meet those that make this place what it is.

As for your problem, you have covered most of the basics. From here, the dealership would be connecting their computer to see if they can talk with the various computers. Because you don't mention having starting issues with the car, I am going to assume that the engine runs. This would then tend to lead to the assumption that the ECM is good. So, you are really looking at a bad ABS module. If you drive, I would assume that the speedo does not move. This would again point to a bad ABS module.

Before we make some big leaps, you don't mention checking the fuses. There are 2 fuses that you need to check. You need to check fuse F3 (60 amp) in the engine bay fuse box and F96 (7.5 amp) in the fuse box under the dash. Either one of these could cause the ABS module to not have sufficient power and therefore lead to it not being able to communicate.

Just for reference, your car actually has the 2003 wiring harness in it. So, when you look at diagrams and whatnot, you have a 2004 vehicle, not a 2004.25 vehicle. Jaguar made slight changes in the middle of the 2004 model year and you are right on the cusp of things.

 

I will go and fill out the new member info.

Thanks for the helpful information.

1. Yes, the car starts and drives fine.......in limp mode....3rd gear only.
2. The speedometer is not functioning.

I will check those fuses tomorrow when I have some daylight.

I did some extensive reading on the forum with every reference to the DTC 1637 and it seems most of the advice was to check the ABS components such as wheel speed sensors, wheel speed sensor cables, the rings in the rear axles, etc... Given the code (and my limited understanding of the short code description) the issue is basically a networking issue associated with the CAN (controller area network). I assume the ABSCM cant communicate with the ECM or vice versa. Which means its the cable between the two modules or a fault in one of the modules that does not allow communication with the other module.

Is it possible that a bad wheel sensor or wheel sensor cable can confuse the ABSCM such that it loses its ability to communicate via the CAN protocols?

Also is there a way to test the ABSCM? (aside from sending it in for a rebuild)

 

I was just looking at my Owners manual that came with my car and it is showing that F3 (engine fuse box) is "not used". And it doesnt show an F96 for the passenger compartment fuse box. It shows those fuses from F1 thru F56.

How can I verify if I have the 2003 or 2004 wiring in my car?
Where can I find wiring/fuse diagrams for this car?

 

Update

Fuse F13 (passenger compartment) 5A checks good
Fuse F41 (engine compartment) is actually on the underside of the fuse box. I couldnt get to it so I check for voltage at the ABS control module instead.

ABS Control Module Testing - I tested the following on the ABS control module connector (disconnected from the ABS control module)

1. Pin 1 to Pin 2 = 11.4 V
2. Pin 5 to pin 6 = 11.4 V
3. Pin 24 to pin 40 = 52 ohms

I also checked the two ground pins to battery ground. In theory these should read 0 ohms. Instead they measured approximately 1000 ohms.

Is this resistance to ground normal? Or did I possibly just find my problem?

I assume I should be reading over 12 volts on the ABS connector but the added resistance is reducing the voltage at the ABS control module connector.

I am unsure as to where to look for ground points associated with the ABS control module.

 

Update

I found the ground point that was causing the problems. It was just below the passenger headlights. I simply removed the bolt, cleaned the connections and my P1637 problem went away.

Lesson learned......having the exact voltage to the ABS Controller Module is imperative to proper operation.

And now I have two other DTC codes set.

P0174 - System too lean (bank 2) - I will start looking for a vacuum leak
C1155 - Left Front Wheel sensor showing open (I think I have a wire that got stretched too far)

Thanks to Thermo for his help.......he got me pointed in the right direction
BTW......my car is the 2004.25 or 2005.50 wiring harness.

The following link provided the necessary circuit/wiring diagrams to get me through proper troubleshooting.

http://www.jagrepair.com/images/Auto...52004.25en.pdf

 

Have you checked your battery and charging voltage? The ground for the ABS is just behind the right headlight. There is two ground bolts, I would check both.