Idle & Off Throttle Hang - Sometimes

[The1]

DTC49 Check Instructions

DTC49DiagP1.png (50.43 KiB) Viewed 4659 times

DTC49DiagP2.png (58.78 KiB) Viewed 4659 times

[The1]

i have distributor test procedure as well if you want it.

[Monarols71]

Thank you. I found the test sheets and resistors, and formatted an old HDD with Win XP on it so I can run the service manuals.
Something to do next weekend. Intermittent faults are always fun. (As if I haven't got enough to do already )
Thanks

[The1]

yep that's it

[MuckUte]

On the code 49.

I was looking for some other stuff during the week and came across THIS

The last post has most of the info,

[Monarols71]

Thanks MuckUte.
It all sounds reasonable to me, but as far as electronics go, I'd make a good hairdresser.
Some of the more electronically enhanced people on here can probably confirm or deny.

But, I'll give it a go, and see what happens. Wiring, I can do.
Maybe some shielded heavy audio or video cable. Pity they didn't make quad shielded RG6 cable with a flexible core.
Cheers

[VL400]

Be VERY careful, GM know what they are doing!

[Monarols71]

I'll go through the proper test procedures first and see if we've got a dodgy connector or something. Obviously some vehicles are prone to it, and most not.
After all that, if it still rears it's ugly head, then I'll try some shielded wiring.
Is there some way of telling when the code is thrown, like when starting or after 5 minutes running or at a certain temperature or whatever?
Thanks

[Monarols71]

List of tests today as listed by GM. Although I don't agree with the outcome.
I'll miss the earlier steps as we don't have access to any Tech tools. Holdon to your wallet want $113.30 just to reset the air bag light We'll buy another BCM, first. As VL400 said, they know what they're doing. Yeah, right. Unless your wife drives a V6 Vectra. Then they have NFI.
Sorry, back to subject.
DTC 49 - Cam/ Crank sensor signal intermittent.
Step 3 - Ignition OFF > Disconnect the PCM connectors > Connect a DVM between the PCM harness connector terminal "D3" and earth > Ignition ON > Is the voltage approx 5 volts = NO > Go to step 4
Step 4 - Bump the engine with the starter > Is the voltage approx 5 volts = NO > Go to DTC 48 in this section

DTC 48 - Camshaft position sensor signal missing.
Step 3 - Use a DVM connected to earth to backprobe the PCM connector "D3" > Start the engine and allow to idle > Does the voltage vary between 0.8 to 1.5 volts = YES > Go to step 8
Step 8 - Replace the PCM. blah blah security link etc.

So I guess we're trying the wiring "fix" now. Try and find a VS hybrid Series 3 V8 PCM for a decent price.

Oh well. At least you people have us on the right track to try and sort it. Thanks.

[The1]

Try another pcm but have vats off and check.