Hey guys! I need serious opinions here! So had engine check light, poor engine performance lights, gauge not reaching golden mid- point….my repair shop ended up replacing (swollen) radiator hoses & tstat tower. Fine for first day, but then back to dash lights and gauge issue. Back in the shop 2 days… mechanic still puzzling over it, but now he’s wondering about car computer system just not communicating. Mentioning replacing computer(not sure yet), which may only be available from New York(age of Jag).
All of which sounds hella-pricey…. And not in my ability to handle.
Opinion? Suggestions?
EDIT: is ECM repair/rebuild the answer here, if that’s the issue? If so, who/where, that wouldn’t mean me selling a kidney?

 

Hi,
Ask your mechanic to read the codes for you, and post them here.

The '97 Engine Control Module is prone to failing, but more investigation is needed before changing out parts on spec (and it may well be repairable if it's proven to be faulty).

 

excellent suggestion! It may be tomorrow, but I will absolutely do! Thank you!

 

For something like $15 on ebay, why doesn't EVERYONE have a simple code reader???????

 

Okie dokie…. Here goes nothing…and I MEAN nothing; mechanic has NO codes to give me. Couldn’t get it to send code, so took the computer out , circuit board was wet, dried it, put it back in. Said it ran, got hot. No codes being sent. Says he’s thinking outside the box. I had absolutely no issues until dash warnings came on and I took it in next day first thing. Am preparing to offer a kidney on EBay..
EDIT: Had a thought here… in the 4 1/2 years I’ve owned this car , it has only been washed by anyone other than myself ,one time… as a courtesy service of the same repair shop , after they worked on it..and it threw same dash lights just like this. They had to hand dry under hood when I took it back in. I think they got water under hood, this time again, and it’s supposed to be on my records NOT to wash car! This time, after first time in, I noticed water on my door frame and thought “oh my, they washed it! Crap!” So, could it be one of the guys washed it, using their car washer, and screwed it up? Asking for a friend.

 

thank you, that’s very helpful.

 

The main reason I got my XKR for $2500 was that the lot I got it from powerwashed under the hood and positvely soaked the fuse assemblies. Trust me, if the fuse assemblies get that soaked, just replace them. If the ECU literally has water in it, you might as well get a replacement as well (part matched exactly) and have it reprogrammed or send it off with your existing ECU to be cloned.

 

I wonder how on earth water got in. The electronic module is in a metal box, which is itself inside a plastic container with some degree of sealing, and then under a protective cover inside the false bulkhead.

I understand that a forum member has volunteered to come to your assistance. Please let us know how you progress, and the best of luck.

In the meantime, I'd suggest disconnecting the battery in the boot if you can so the electronics & wiring aren't powered up.

 

Hey, thanks for that! Any reason I can’t drive car 2 miles from repair shop to my home… to get it out of their hands? I do have AAA, so I can tow..

 

If it will make the journey then you could. If you're unsure, then best to use the backup.

 

And keep drying that area with a hair dryer. It may take a day or two of effort, but you may get lucky and resolve your issue when everything is completely dry again....

 

I,m at Rosevillesister's to try to diagnose here 97 xk8.
I'm thinking it's the battery. My info

Before starting check the codes. No communication.
Checked battery. Showing 12.4v and the date on the
battery is 6/19
Started car. Battery at 14.2v
Turn on A/C coolong fans come on.
Checked for DTC again while running and it's reading sensors and shows NO DTC.
Other opinions appreciated.
Bob

 

Hi BobRoy,

A failing '97 ECM will usually throw spurious DTCs, so perhaps the car just needed to dry out from however it got wet. Am I correct that 'reading sensors' means you're seeing live data from the car, hence your reader is getting comms OK?

The battery may be marginal, but I'd be expecting the ABS to be complaining, or windows losing their memories as first signs. I guess at >6 years it's getting tired, though.

Not sure if this helps much - it's hard to be any more definitive when the car isn't complaining - is it driving OK, no warning lights?

 

Hi Michaelh,
I had no communication with the ECM with key on engine off.
When it was running I got communication with the ECM and
I got live data. There were no lights or warnings on the dash, except for door and trunk open.
She told when she started it earlier this morning there was a
rough idle that went away.
If I remember from the forum that the electronics don't like it when the voltage is below 12.6v.
I didn't check to see if the windows were working properly.
The live data I checked was engine temp, 181, and Battery
Positive,central processor, unit 1- I got 3 readings 14.20v 1.02v,
and 7.69v. I know what the 14.20 is but not sure what the 1.02v and
the 7.69v mean. Maybe you or someone else knows.
The engine was running normally and didn't see any obvious issues.
If you can think of something else I should check I can go back to her house and check it out.
Thanks,
Bob

 

Perhaps there was some water that found its way under the coil covers, and has dried out with the engine heat?

The ignition-on comms does seem suspect (I don't see activity on my car with ignition off):- not sure what the voltages you're seeing on the reader relate to - other than the 14.2, which is presumably the battery voltage with the motor running.

What kind of reader are you using? I'd expect to see engine rpm, throttle position percentage, etc. - even from a simple ELM327 reader.

 

Hi I have a 97 as well usually this kind of issue is the capacitors on the ECU if they are going bad. If you open the ecu and see bulges on top of the capacitors they are bad and can cause all kinds of random issues. The picture below shows the one capacitor bulged and leaking. This is very common on the early cars. Easy fix just have them replaced. It should be done before the capacitors pop and ready damage the tracing on the board.

 

I have a iCarsoft i930 scanner.
I picked those two for live data to see if I was getting the same reading from the ECM that I was getting from my tester at the battery while running. I checked the temp because she had an reading on the dash that was a little below normal.
I'm thinking she should replace the battery due to being 7 years old and having 12.4v, it could be even lower if the car sits for a couple of days. I could go back to get more readings if you think it would help.
I think do the battery now and drive it normally to see if any codes reappear. If they do I can check it with my scanner.

 

My opinion, for what it's worth, those voltages you are getting are fine, as the car is running ok, you don't have codes and you can communicate with the car. I don't know what the voltages are you are looking at, but not everything has to be 12v or zero, so we can't really draw any conclusions from those values.

If it were my car, I would use silicon sealant or tape to make the ECM module itself watertight, and the computer compartment watertight. Look for any way water can get in through the rubber grommets into the computer compartment, make sure the cover screws down firmly and check to see if the drain holes at either end of the windscreen aren't blocked. I would be amazed if it wasn't the water ingress that caused all these problems - either way it wouldn't have helped and it is definitely worth making sure it can't happen again.

 

When I went to see the car I forgot my torx bits so I didn't check the ECM. Next time I go back I will bring them and check the condition of the ECM.

Visually looking at the box I couldn't see how water got into the ECM box.

 

The nice thing about the 97 is it does not have the security key transponder installed so a computer swap is possible too, if you let me know the model of tge computer the LJA1410AH is the most rare but the LJA1410AK AND LJA1410CA are pretty common I have shaped a LJA1410AH with a LJA1410AK and had no problems initially a few codes but after running it and then resetting codes no problem. If you can not communicate with the ecu it is a high likelihood the capacitors issue