Ok, so the SSD computer program was an easy install on my PC but once I hooked it up to my Mongoose it read that my PCM was not communicating with the car.

This is a no start/no crank condition related to a ground side switched VVT solenoid we spoke about before on this forum.

What's next?

I opened the PCM and there's a little flux discoloration around the pins and one of the little brown resistors looks darker than the others but the computer guy I shot a picture to said the board looked fine on visual inspection. I think it's time to back track a little and view the harness, pin some things and try to locate the bad pin or exact location of the fault. I would hate to scrap a $1500 PCM only to find out it was a fuse in a harness somewhere else in the vehicle.

Please follow along, comment or leave your "new battery" suggestions as we go!

UPDATE 1: I just checked the harness and the pins look clean and polished and we tried the CANbus pin 4 and 6 test previously to test the connection in the wiring outside of the PCM itself.

Unanswered Questions:

What other pins can I test and where?

The computer guy said something about a diagram for the PCM but I can't find one. It sounded like he said the word Mitchell. I bought a repair manual but it didn't seem to include that level of detail with the PCM repair but there were a few different areas showing pinning procedures and one threat here I have bookmarked.

Does anyone have experience with a reliable PCM repair company?

 

hi
is sdd comunicating with any thing else, should pickup at least 20 plus modules on the car, engine ecu is just 1
is it reading the vin, you need to make sure it reads the car vin first so you know it communicating
if nothing coming up then its usually the driver for the mongoose lead
cheers
Joe

ps if you need wiring diagrams look here JagRepair.com - Jaguar Repair Information Resource

 

Yeah, man and it reads it all. At first some of the parallel modules were showing warnings but I did something to reset it and they light up again. Only the PCM is at fault and the potential problem was warned in a few places online by professional car guys doing tutorials on the solenoid and/or ground side switching. I just don't think anyone out there really knows to what extent it would damage the system and so I'm slowly starting to figure it out.

Good question.

The more I understand about ground side switching the more I realize the circuit should be able to keep what I thought was a ground wire hot and switch it between the solenoid and computer. Surely, whatever that switch is went out or was closed so shocked the brain or something. My guess is that the switch is one of those little resistors/capacitors with polarity and that it would perhaps prevent a charge going through the opposite direction and from there it goes to the ground and switches the solenoid and this all somehow happens at the speed of the VVT. One possible test is to buy a pair of smart tweezers to test the caps while still on the board... $25.

 

I want to try this but don't follow.

"It’s always important to consult a wiring schematic and make sure that all power and ground connections are clean and functioning correctly. I often use a small, homemade bulb tester to load both power and ground connections with about one-half ampere of current flow. In some cases, I brush a very small amount of electrical conductivity enhancer like Stabilant 22 on the PCM pins just to make sure I have good pin contact. In other cases, it’s advisable to check the tension fit on individual pins, either with a special tool, spare mating pin or drill size."

Is he back probing with the harness on or does he have it removed? Anyone?

 

I have no experiance of this so i may not be any help, however....

What version of SDD are you using?
It may not be this, and I could be wrong but I think SDD will not comunicate with the PCM if it has been updated with a later version than the one being used.
I think SDD 130 has the latest update software? But again I could be wrong.
Also sometimes if the battery voltage is too low SDD will stop communicating with units. (There is a battery status reading on SDD so you should be able to see if this is ok.)

However as I said i have zero experiance myself so this may not help you at all!

Mellow

 

Here are a couple of really good articles I found about the PCM not communicating.

https://www.searchautoparts.com/moto...-breakdown-pcm

https://www.autozone.com/repairguide...96b43f80e65203

https://www.underhoodservice.com/pcm-overvoltage/

Hey, you may be right about the SSD not reading it and the one I use is 138. That's later than 130 but it shouldn't matter should it? It does say something about an update being needed for all features but let me also say I'm getting a PATS 24 signal suggesting a failure to read the PCM and so will follow up on this in parallel to some of the pin tests and removing sensors (starting with the one that started this).

 

Do you have the spa files for your sdd version....they are pinpoint multimeter tests for everything electronic

 

Hey, the look of your 06 white STR...

I . don't have it and went on to my next step and bought a pair of "smart tweezers" and tested the little brown capacitors on the board. This turned out to be a good idea that may save me a lot of money if everything pans out right. Visually, the shock appeared to darken a few around the pins and cause some flux discoloration where the rest of the board is super neat and clean. I assume it dissipated the charge as a safety and/or one of the capacitors took the brunt of it and blew. Why or how doesn't matter if one is faulty and the learning curve on this stuff is pretty high so I started to poke around with tools that could give me a capacity reading on board.

What I found was that most were showing a certain amount and one was showing no capacity. Now this could either be it's a different type or something is affecting it that I don't know but so far I think I may have found the culprit.

Next steps: More research on types of capacitors and buying tools to remove and replace. I already bought the flux and heat gun and will get a little soldering iron and some desolder and copper wick etc. I'll swap it out and see what happens...

 

Sounds like you have the knowledge to head in that direction....i am lost when it comes to circuit boards and the like....good luck and i bet you whip it soon