U1016

[mr.prick]

i could not find GM.VATS
unplugging the IPC alone off the bus gave me intermittent VATS
active-inactive, U1016, U1040, U1096, and, P1626.
i imagine that any module off the bus will cause Uxxxx codes and
maybe a non connect.

when the car starts it reeks of gas.
but forget about the non running condition,
i want to connect completely to flash.
i don`t see why i cannot connect completely to flash/read.
i am going to test my V2 on someone else`s car to see if i have an
issue with flashscan. (i doubt it)

LOL
are you saying i wasted my time with the continuity tests?
from what i`ve read, a continuity test should be enough
as long as it passes, if it does not then you look to see if it is
shorted to ground or power.
i`m about ready to give up and have it towed to a dealership.
but i`m leary of them not being able to find the problem.

[joecar]

Oh, GM.VATS might be a later PCM...

Hmmm... I just remembered unplugging the IPC may cause the PCM to complain because it sends VSS messages to the IPC...

Your continuity tests are good...
I was just saying I prefer measuring volt drops, but that's not always feasible.

And you're certain that all the grounds are good...?
And you're certain that all the fuses/links are good...?

when the car starts it reeks of gas.

I'm beginning to think your PCM may be half dead...
Do you have a spare PCM that's already programmed...?

When it doesn't start, are you certain it is due to no spark...?
If so, have you tried diagnosing the no spark...?

i`m about ready to give up and have it towed to a dealership.
but i`m leary of them not being able to find the problem.

Some technicians are good, they will pinpoint the component and replace that only...
while other technicians will shotgun and replace everything in sight.

[mr.prick]

do you know if one of the modules were to be disconnected,
if flashscan could read/flash the PCM?
maybe disconnect one of you modules then check status of your PCM for me.

[joecar]

That would be a good test...
remove all modules from the bus except the PCM...
then try to read the PCM's flash...
if that works, turn key off, add another module, and try again;

if the PCM is the only module and you can't read from it, then:
- check that the PCM's power/ground connections/wires are all good;
- check that battery voltage is at least 12V.

[joecar]

When a bench harness is used, the PCM is the only module present, and the tunetool can read/write the flash...

I can't pull my car apart right now, I'm still at work...

[joecar]

You may want to inspect the PCM's pins... see if any are bent or pushing in.

[joecar]

When it doesn't start, are you certain it is due to no spark...?
If so, have you tried diagnosing the no spark...?

I'll dig thru the service manual tonite to find the pages relevant to this.

[mr.prick]

i have the stock PCM in right now.
the last time this happened i could not read the VIN with RR installed,
then i put the stocker back in and it could not connect either.
for some reason the condition went away.

there where a few times while driving down the road,
the car just went way lean even with the RR added fuel like crazy.

if it is possible to remove all other modules except the PCM
from the stock harness and still connect to flash/read
then i could nail it down to a module failure,
i just need to be absolutely certain that by unplugging the other modules
from the stock harness that it will or will not cause this problem
on a working vehicle.

[joecar]

Oh, when you unplug or plug a module's connector(s), you have to have the battery disconnected first.

[mr.prick]

Oh, when you unplug or plug a module's connector(s), you have to have the battery disconnected first.

ok
i`m just going to unplug the module`s wire at the star bus,
unless i should completely disconnect the module of the harness.
i wonder which way would be best.