Jolls VY SS Ute Project (Jimi Hendrix)

[Jolls]

I didn't have any assistants to help with the gearbox so it took a bit to balance it on two jacks to clear the clutch and the firewall/transmission tunnel. After a bit of mucking about getting it into position it pretty much fell into place. Then removed the diff and tailshaft from the VZ and swapped them straight across. Fitted up a new clutch master cylinder and heater tap. Fitted up the exhaust and ready to go - time to start him up.

Crank, crank, crank - no start. Not even a hint of it. Couldn't hear the fuel pump kicking in so expected that there was a security issue. Pulled out the Tech 2 and sure as eggs a no start signal from the PIM and slip ring and associated no comms between modules. Called it a day.

Back out this morning to bleed the clutch and do dome investigating. Found a "spare" control module of some sort in with the cabin plastics. After a bunch of research figured it to be the fuel pump control. So I pulled the cabin apart - ripped out the seats, sub woofer and the rear carpet wall and there it was sitting there. Connected up the fuel pump control, cleared all the DTCs and prep for start.

Turn key, fuel pump kicks in. Crank, crank, crank nothing from the noisy piece at the front. Tech 2 back on - same DTCs - slip ring failure and no start signal from PIM.

I expect this is a security issue based on the slip ring failure. The key has no battery and despite the key head being taped together it probably isn't reading the chip. However, reading the manual there is contradictions between what the manual states and the DTCs that are being thrown.

From the manual - on vehicles with a GEN III V8 engine, the BCM polls the PIM and sends an encrypted BCM / key security code when the ignition is turned on. The security code is received via the BCM slip ring, or via the remote receiver in the event of no slip ring communication. The PIM compares the received security code with its stored security code and if the codes match, enables continued engine cranking and sends a separate encrypted security code to the PCM. I think we get at least that far; however, if there is a slip ring failure how do we get to crank the engine?

Then the PCM compares this code with its stored security code and if the codes match, enables injector fueling to continue. The PIM returns an OK TO START message to the BCM, which tells the BCM to jump from SHORT LOOP mode to LONG LOOP mode.

The BCM is currently returning DTC P1626 THEFT DETERRENT SYSTEM FUEL ENABLE CIRCUIT. The circuit description says that after the BCM has confirmed the correct key has been used (via the slip ring) the BCM sends a password to the PIM via the UART Serial Data circuit. The PIM will operate the starter motor (it does), and supply another password via Class II Serial Data to the PCM. When this password matches the password stored in the PCM, the system enables the fuel injection. If the BCM does not send a password or if the PCM does not receive it, the vehicle will not start. So this indicates a data transfer issue between the PIM and PCM (maybe?)

I have new keys on the way that I trust I can successfully link to the BCM and we will see how it goes. For the time being - Jimi is relaxing in the shed waiting for the keys to arrive.

Cheers n Beers
Jolls

 

[losh1971]

I love your persistence. I reckon if something became this complicated for me I'd be looking to outsource it.

 

[Jolls]

It took me months to solve the VZ accelerator pedal issue after the previous owner cut the connector off. Fu took a photo of his and posted it and I the colours were in the wrong place. Turned out the manual had incorrectly numbered the pins on the connector. Changed it to match and problem resolved.

This is just the start of this one - I trust it will be resolved easily. If not I guess I will be learning a bit about serial and UART interfaces!

Cheers n Beers
Jolls

 

[Fu Manchu]

I’m not sure where it is just now, but @OldSkoolGP went through something similar with his E38 ECM conversion on his GTO. Thread is in VZ somewhere

 

[Fu Manchu]

I have a picture of the circuit somewhere on my laptop. I might post tomorrow for others to follow easier.

 

[Fu Manchu]

I think part of the issue and the final piece of the puzzle was the clutch switch. He had to leave foot off clutch to start.

A later episode went on to resolve that further.

 

[Jolls]

I’m not sure where it is just now, but @OldSkoolGP went through something similar with his E38 ECM conversion on his GTO. Thread is in VZ somewhere

Thanks mate - will dig it out. Would rather learn from someone else than through my own trials and errors.

 

[Fu Manchu]

https://forums.justcommodores.com.au/threads/looking-for-help-from-down-under.292837/

 

[Fu Manchu]

Not sure if this was posted in the thread.

 

[Jolls]

https://forums.justcommodores.com.au/threads/looking-for-help-from-down-under.292837/

Thanks Fu, found them earlier this morning and read through the lot and watched what videos were relevant. I'm not sure why Billy's posts have disappeared, but is looked like he had some valuable experience to add. I am hoping that I don't have to learn the programming side of the house but will if it gets me to the finish line.

I have spoken tot he previous owner and he tells me that it was all running as it is - the only change is that the PCM was converted to manual from automatic by OzTrack in Sydney. I haven't looked into that side as yet because of the slip ring DTC. I expect that the slip ring not having the right checksum means that the a code is not sent to the PIM/PCM and as such the PIM shuts down the fuel/ignition circuit. I'm going to play with this side of the hose - cleaning the slip ring, checking connections etc with the Tech 2 in normal mode when I get a chance.

Watched the video and the update - honourable mention I note!

Cheers n Beers
Jolls