Quick update on my wife: She is still on the early AM dialysis every other day. But her cancer returned in her cheek below the eye they took out. She had radiation treatments fr a number of weeks and just finished the series. The skin on her face is burned from inside, but she is healing. Next will be a PET scan to make sure it is all gone. But, she's hanging in there and trusting God.

 

Don;

Back to my original and ongoing problem: First, thank you, CR Bass and Mad Hatter for trying to help me.

I can't help but think that if both my ECU and the ABS module working OK, there might be a problem with the CAN harness. Not sure how that fits into having a month of no lights working condition, and then back to the failure. I THINK said I performed a continuity test of critical sections of the harness (from an earlier post), but as time goes by I forget. Notes and this forum suggest I did that.

Then, CR was kind enough to lend me his analyzer, which I tried to use. I'm not sure if I did it right, but I still have no answers. I am wondering if I should take it back to the $billion shop and tell them to check the CAN harness with their $Billion analyzer. Not sure if I said it, but they did find a P1799 code on my first visit. I don't know how that fits.

I will call GINO and see if he'll retest the ABS module he repaired, but then, I have a different one in there now. A sensible person would have removed the replacement module and sent BOTH f them to him for testing. But nooooooo.....not me.

Anyway: CEL + ABS + "STABILITY CONTROL FAIL" + that "ASC" light on the dash/console are glowing at me after several restarts.

What should I do next??

Ken

 

Hi Ken,

Your wife and you are on such an horrific journey! I will keep praying for you both.

Regarding your car, you do need to scan for codes with a system capable of reading Powertrain (P-prefix), Chassis (C-) and Network (U-) DTCs. With your symptoms, there will be codes stored in multiple modules, and without the codes, you are guessing blindly.

If you still have one or more codes for the CAN, the network runs on the twisted pair of yellow and green wires which are usually easy to see at all the associated system connections. In addition to the connections at the ABS/TC Control Module, TCM and ECM, there is a harness-to-harness connector, labelled LF40, located in the engine bay inside the "left hand enclosure." It would be worth checking that connector for corrosion, looseness, or contamination with water or oil. You should be able to identify the connector because it should have a yellow/green twisted pair connected to each side of the connector. It would also be worth checking the connector at the transmission for oil contamination, since the ABS CAN circuit passes through the TCM:







Cheers,

Don

 

That's good! Thank you. I'll recheck all those connections.

You just reminded me that the last two times I drove the car I had some glitches with the transmission shifting. This was something new...before I replaced the pump/module unit. The car seemed to shift into a gear so high it would hardly accelerate. Very sluggish until it got up to about 40 mph. Even then I did not try to accelerate or push it. Just limped it home. Last time I drove it after the brake fluid flush it seemed normal, but I didn't take it out of the neighborhood or above 30-40 mph.....gently.

My son told me that when he first turned the key on after the R&R to see if there were any codes, he got a "Gear Box Fault" message (on the instrument cluster, I think). It went away and hasn't returned with several start-ups. Does that tell us something???

 

When the Gear Box Fault warning lamp is illuminated, the transmission is commanded into Limp Home Mode, so it's locked in one higher gear, maybe 3rd or 5th (I can never remember which it is for the different ZF transmissions). The car will drive, but it will feel as though it has no acceleration.

Whenever the GBF warning is illuminated, diagnostic fault codes will also be triggered, so scanning the vehicle should give you some clues.

There are many possible cause of shifting issues, including counterintuitive things like the MAFS, a wheel speed sensor, engine misfires, etc.

 

Thanks, Don; I have not been able to drive the car, but I had my son run another scan with the Autel. Same codes P1000, P1637, and C-1137. But this time he got a message about the CAN: "Network Malfunction CAN" I think. That's new as far as I can remember. Does that tell us something?

Ken

PS: Wife is hanging in there,healing from the radiation burns. UGH!

 

Hi Ken,

The P1000 DTC just means the I/M (inspection & maintenance) readiness monitors have not completed since the last time the codes were cleared. You can disregard this code - it should reset to P1111 once you've resolved the other codes and can drive the car normally for a few trips.

Here are the definitions of the P1637 and C1137 DTCs:





So you have DTCs for a fault in the CAN circuit between the Anti-lock Brake System/Traction Control Control Module and the Engine Control Module, and a fault in the Dynamic Stability Control Module (which is built in to the ABS/DSC module). Off the top of my head, this suggests one of the following:

1. My recollection is that you had P1637 prior to replacing the ABS/DSC module, so the cause of this code may be wiring rather than the module;

2. C1137 could simply be a new development related to the same issue causing the P1637, or it could mean the new salvaged ABS/DSC module has an internal problem; Note that these modules are notorious for solder joint failure on the circuit boards. The joints did not receive enough solder at the factory, and were often "cold," meaning the circuit board traces and component leads did not reach the necessary temperature when the solder was applied. Over time, the solder tends to crack, causing an open or intermittent circuit. This happens most often to the two large pins for the hydraulic pump motor connector, but I have found that as many as half of all of the solder joints on one of these circuit boards may be starved, cold or cracked. The solution is to re-flow and supplement every solder joint on the circuit board.

Have you checked the connections I mentioned in post #203?

Cheers,

Don

 

My son and I looked at those drawings. I thought we had done this check at the plug under the left side of the dashboard, but maybe that didn't get the right pins? We didn't find any breaks at that time. But if we want to check the continuity of just those two wires do we pull the connectors and check in stages, or should we just check from the ABS module connector and at the ECM connector? At some point does a check need to be done with power to the circuit?

 

You can certainly test from the ABS module connector to the ECM connector, but it would be worth checking that intermediary connector for any signs of contamination, corrosion, looseness or damage.

Section 418-00 in the 1999 Workshop Manual describes the communication networks and their operating characteristics. It dawned on me that there might be a diagnostic routine in the manual for P1637, and sure enough, there is:
















Cheers,

Don

 

ojl, afraid I cannot offer any useful info, but I just wanted to extend my best wishes to your wife and you and also to comment on the remarkable tech support Members have shown. The Forum is a priceless resource for Jag lovers (old and young). I know I’d never have even bought my XK8 if I hadn’t known of the incredible amount of info and assistance available here.