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My brother just changed the front hubs on his VS Commodore. He got sold a set of IRS hubs but he has a solid axle so naturally the ABS warning light came on. Probing for error codes (using a paper clip) confirmed the sensor frequency fault.

He then installed the correct hubs and went to check that the error code had been cleared (after disconnecting the battery, of course) but got nothing -- no flashes at all, not even the "all good" sequence. I tried my ALDL-USB cable and couldn't connect via TunerPro either. He also tried swapping his BCM for a spare I had lying around -- nada!

(FWIW he converted to LS1 a couple of years ago, so there is no PCM on the bus, but everything has seemingly been fine without it until now).

We're both at a bit of a loss... Hoping the gurus here can point us in the right direction.

Sooooo... LS1 ECU hooked up? And LS1 communication wire run to the diagnostic port (Pin 2)??

LS1 ECU does not communicate over ALDL... this is why you will not be getting any information using TunerPro. Also the paper clip trip will also not work if you have removed the original VS ECU.

Paper clip should still work to flash ABS codes, am I right?
You won't be able to communicate with tuner pro with the LS1 I believe.
Has the ABS light now gone out since you disconnected the battery?
Maybe it's all fine now? Does the ABS work?

As far as I'm aware the only things on the bus are BCM, ABS and PCM. Is the ABS even on the bus in a VS? If the LS1 conversion has removed the PCM and there's no need for BCM/PCM Comms for anti theft then there's no use for the bus other than diagnostics?

If the lights out, I would go down a dirt road and lock it up and see if it works.
If it is then disconnect a wheel speed sensor and confirm it brings the light on. Try flash the codes with the paper clip with the fault. If it flashes then, plug it back in, disconnect the battery again and clear the light.

Pretty sure VT was the first model to use the bus system

If the abs is still connected to the obd plug, then paper clip trick should still flash fault codes

Thanks for the replies. To answer your questions:

Tazzi wrote:Sooooo... LS1 ECU hooked up? And LS1 communication wire run to the diagnostic port (Pin 2)??

He has a second OBD connector in the glove box, just for the LS1 PCM. The OBD connector under the fuse panel only has BCM and ABS since the conversion.

Tazzi wrote:LS1 ECU does not communicate over ALDL... this is why you will not be getting any information using TunerPro. Also the paper clip trip will also not work if you have removed the original VS ECU.

I attempted to run TunerPro on the BCM/ABS connector but if the software needs a PCM then I guess that failure is a red herring. The paper clip trick was working on the BCM/ABS connector right up until the second hub change.

pman92 wrote:Paper clip should still work to flash ABS codes, am I right?

Correct. The mystery is why it stopped working between the two sets of hubs.

pman92 wrote:You won't be able to communicate with tuner pro with the LS1 I believe.

Yes, I think you're right. But I wasn't trying to

pman92 wrote:Has the ABS light now gone out since you disconnected the battery?
Maybe it's all fine now? Does the ABS work?

He took the IRS hubs back to the store and got a set of live axle hubs. ABS seems to be physically working now but the light is still on, which is how he discovered that the paper clip trick stopped working.

pman92 wrote:As far as I'm aware the only things on the bus are BCM, ABS and PCM. Is the ABS even on the bus in a VS? If the LS1 conversion has removed the PCM and there's no need for BCM/PCM Comms for anti theft then there's no use for the bus other than diagnostics?

Correct on all counts.

Biggvl wrote:If the abs is still connected to the obd plug, then paper clip trick should still flash fault codes

It did when he had the wrong hubs on and was helpful in diagnosing that problem. But now he has the right hubs... nothing