MERGED-(Fresh opti pull pics) & (Ignition stutter-Code crackers needed)
07-16-2008, 10:18 PM
#61
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Diagnostic aids (for intermittent H41, 42) "Since the coil driver gets it power from the coil (???), check the ignition feed circuit to the ignition coil for opens."
Those 2 pink wires - circuit #239 - from the ignition, control DTC 18, 41, 42, (not 34 tho').
Since the ICC fault DOES come up when it's hot, it HAS TO be CURRENT when you actually shut down hot, NOT HISTORY. In the a.m., I'm gonna' warm it up, till it starts the 'misses', and try to test some connections while it's still hot. You should do the same also.
I'm almost 99% positive that the problem is the PCM having a problem with physical heat, OR, a loose connection between the ignition switch and the PCM.
Gimme' a minute to sort thru the schematics as I scan them... I'm tryin' to solve this for myself too.
Last edited by schrade; 07-17-2008 at 02:10 AM.
07-16-2008, 10:52 PM
#62
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Intermittents: (FSM) See ignition feed circuit 1st pic - top of schematic 2 pink wires circuit #239:
THEN follow back to in-dash fuse block 2nd, 3rd pic..., and notice what else is powered BESIDE the pink #239, which DO WORK (red circle)...
THEN follow back to in-dash fuse block 2nd, 3rd pic..., and notice what else is powered BESIDE the pink #239, which DO WORK (red circle)...
07-16-2008, 11:39 PM
#64
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AND NOW, as I think on 'ignition switch' and it's connection in the link..., how 'bout this? Ignition switch solenoid fault???
This is an ignition switch (not starter) solenoid from a '98 GMC Jimmy pic 1.
The part might be different on early '90's vettes, and it might NOT be different - it was used on GM S-vehicles (and some other GM's) back to AT LEAST '94, from 2003. The manufacturer of the part was surely the same for all GM ignition switch solenoids.
Observe how many stray codes are tripped when it fails! And they are INTERMITTENT too!!! (I had one).
Could this be the problem???
ed.:
Couple of issues with this ig switch solenoid bein' the problem... the 'miss' comes up when the motor gets fully warmed up. The motor's heat doesn't get into the steering column harness area under the dash, where this device is. Thoughts???
Where's this guy?
http://forums.corvetteforum.com/show....php?t=2076155
This is an ignition switch (not starter) solenoid from a '98 GMC Jimmy pic 1.
The part might be different on early '90's vettes, and it might NOT be different - it was used on GM S-vehicles (and some other GM's) back to AT LEAST '94, from 2003. The manufacturer of the part was surely the same for all GM ignition switch solenoids.
Observe how many stray codes are tripped when it fails! And they are INTERMITTENT too!!! (I had one).
Could this be the problem???
ed.:
Couple of issues with this ig switch solenoid bein' the problem... the 'miss' comes up when the motor gets fully warmed up. The motor's heat doesn't get into the steering column harness area under the dash, where this device is. Thoughts???
Where's this guy?
http://forums.corvetteforum.com/show....php?t=2076155
Last edited by schrade; 07-17-2008 at 12:04 AM.
07-17-2008, 01:02 AM
#65
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Whatcha' find out?
HEY! Wakeupbitch!!! I'm LOFRMAO (layin' on floor readin' my assoff)
HEY! Wakeupbitch!!! I'm LOFRMAO (layin' on floor readin' my assoff)
Last edited by schrade; 07-17-2008 at 01:06 AM.
07-17-2008, 02:33 AM
#66
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This is a 12V jumper. If the miss happens, it is a faulty PCM, or the fault is in the 12 V source coming into the fuse on circuit #210.
If the miss happens, first try another 12 V source into #239 out to PCM connectors B30, and D3.
If it still misses, the PCM is most likely bad. (I say most likely, because I have checked out the ICC circuit already (module, opti, coil, engine block ground)).
Enough LOFRMAO for the night.
07-17-2008, 09:48 AM
#67
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Good God, man!!! I'm at work now!!!
Thanks for all the info. Let me hack into my Vette tonight after work...
EDIT...I may just try to swap in another PCM to see if that fixes things also...
Thanks for all the info. Let me hack into my Vette tonight after work...
EDIT...I may just try to swap in another PCM to see if that fixes things also...
Last edited by zeitgeist57; 07-17-2008 at 09:52 AM.
07-17-2008, 04:09 PM
#68
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Still searchin' for the H41 intermittent...
And now we're doin' circuit by-pass INTO PCM from fuse block.
The circuit is #239 Ignition feed circuit. This circuit also controls MANY other parameters, so it is a good test to note.
I used a non-zinc paper clip to probe the PCM connector - better conductor. I also gave it an edge, instead of blunt end, to not push connector pins out of the way. Twist it as you push. I stopped just short of going all the way to the connector face, to not push the female part sideways. You might be able to see it next to the pin in the 4rth pic.
Then I tested for continuity by puttin' another clip into the front of the connector, and checkin'. It's hard to see the black MM probe I'm pinchin' there...
And the same procedure for the split-off of circuit #239 ignition feed wire. See FSM schematic here
http://forums.corvetteforum.com/atta...5&d=1216262888
The circuit is #239 Ignition feed circuit. This circuit also controls MANY other parameters, so it is a good test to note.
I used a non-zinc paper clip to probe the PCM connector - better conductor. I also gave it an edge, instead of blunt end, to not push connector pins out of the way. Twist it as you push. I stopped just short of going all the way to the connector face, to not push the female part sideways. You might be able to see it next to the pin in the 4rth pic.
Then I tested for continuity by puttin' another clip into the front of the connector, and checkin'. It's hard to see the black MM probe I'm pinchin' there...
And the same procedure for the split-off of circuit #239 ignition feed wire. See FSM schematic here
http://forums.corvetteforum.com/atta...5&d=1216262888
07-17-2008, 04:15 PM
#69
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Now I'm tappin' into the fuse panel fuse #33 ECM ignition feed. This is a LIVE 12V feed, so care must be used to prevent shorting out. I've taped the wire, and the alligator clip is not near a metal surface, only rubber. The Aclip is binding the two paper clips, since they merge to circuit #239 to go off to fuse panel.
I tested again continuity from paper clip to paper clip to make sure of connection. With the ignition switched ON, it should show 12V comin' in thru the paper clips.
If I get H41 when I test ride, it will tell me that the fault could be BEFORE the fuse panel, on circuit #210, which is the same as #239, only from the ignition switch, TO the fuse panel, ACROSS the fuse to #239.
I tested again continuity from paper clip to paper clip to make sure of connection. With the ignition switched ON, it should show 12V comin' in thru the paper clips.
If I get H41 when I test ride, it will tell me that the fault could be BEFORE the fuse panel, on circuit #210, which is the same as #239, only from the ignition switch, TO the fuse panel, ACROSS the fuse to #239.
07-17-2008, 04:23 PM
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http://forums.corvetteforum.com/show....php?t=2069247
post 46, 47.
You absolutely HAVE TO make sure of connections as described...
There's your test procedure - same as mine. I'm gettin' ready test ride, to rule it out as the problem.
If the problem doesn't light up, I'll secure the rig better for a few days to make sure, then I'll be able to say the fault IS between the fuse panel and the PCM.
If it does light, I know 1 MORE PLACE THE FAULT IS NOT.
Cross yer fingers, yer toes, yer eyes, legs, teeth, cross yer stinkin' hair too, cross EVERYTHING!!!
ed.:
Prepare a bypass, but don't tap into the ECM fuse yet...
I'm still gettin' that cookin' smell too, with smoke at the passenger cylinder head rear. I cannot see ANY oil comin' from the V/C gasket. It's new.
post 46, 47.
You absolutely HAVE TO make sure of connections as described...
There's your test procedure - same as mine. I'm gettin' ready test ride, to rule it out as the problem.
If the problem doesn't light up, I'll secure the rig better for a few days to make sure, then I'll be able to say the fault IS between the fuse panel and the PCM.
If it does light, I know 1 MORE PLACE THE FAULT IS NOT.
Cross yer fingers, yer toes, yer eyes, legs, teeth, cross yer stinkin' hair too, cross EVERYTHING!!!
ed.:
Prepare a bypass, but don't tap into the ECM fuse yet...
I'm still gettin' that cookin' smell too, with smoke at the passenger cylinder head rear. I cannot see ANY oil comin' from the V/C gasket. It's new.
Last edited by schrade; 07-17-2008 at 05:45 PM.
07-17-2008, 04:49 PM
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Just got back. No code.
Then I looked at the temp guage - 201. Damn. The fault almost always comes up at 215 - 220. It's runnin' now...
Up to 228, no problems, no miss, no light, fan on, up to 231, back down to 227, and the SES lights up. H41.
My bypass is still showin' power at the clips goin' into the PCM.
Next step will be to tap another power source from the fuse panel. Gotta' check for another 'switched' 12 V source.
Can 'unswitched' 12 V be run into the PCM??? ed.: NO - I just tried 12V from the horn 'unswitched' power. No crank. VATS thing?
Now we gotta' find circuit 210 from the fuse panel to the ignition switch. Following it all the way through the dash ain't gonna' happen...
Then I looked at the temp guage - 201. Damn. The fault almost always comes up at 215 - 220. It's runnin' now...
Up to 228, no problems, no miss, no light, fan on, up to 231, back down to 227, and the SES lights up. H41.
My bypass is still showin' power at the clips goin' into the PCM.
Next step will be to tap another power source from the fuse panel. Gotta' check for another 'switched' 12 V source.
Can 'unswitched' 12 V be run into the PCM??? ed.: NO - I just tried 12V from the horn 'unswitched' power. No crank. VATS thing?
Now we gotta' find circuit 210 from the fuse panel to the ignition switch. Following it all the way through the dash ain't gonna' happen...
Last edited by schrade; 07-17-2008 at 06:25 PM.
H72 VSS loss. I think the PCM needs butter, cause it's
07-17-2008, 07:57 PM
#74
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I fed the 12 V horn fuse power into circuit #239, to see if the #239 source was shaky. That's an 'unswitched' power source. It wouldn't start then; I thought it was a VATS activation. It wouldn't start at all, even after unpluggin' the battery. So I thought I toasted the PCM (which might be well-done anyway).
It started this time, went to 228 okay, again, came down, fan off at 219, and I switched off.
Codes lit up H41, and still the H72.
PCM is havin' figmentatious hallucinations.
Next we'll try pullin' the fan fuse, and let it run a few minutes more, shut down, and see if it tripped the codes again.
It started this time, went to 228 okay, again, came down, fan off at 219, and I switched off.
Codes lit up H41, and still the H72.
PCM is havin' figmentatious hallucinations.
Next we'll try pullin' the fan fuse, and let it run a few minutes more, shut down, and see if it tripped the codes again.
07-17-2008, 08:23 PM
#75
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I pulled the fan fuse for the cooling system, to see the effect on H41.
I let it go to 232, and then shut down.
Then plugged into ALDL.
H72 VSS loss again (I stayed in PARK, so no good code), and H77, and H78 (primary and secondary fan circuits - no problem, since the fuse was pulled).
NO H41!!!
Thread pics up at
http://forums.corvetteforum.com/show....php?t=2066961
post #37.
I let it go to 232, and then shut down.
Then plugged into ALDL.
H72 VSS loss again (I stayed in PARK, so no good code), and H77, and H78 (primary and secondary fan circuits - no problem, since the fuse was pulled).
NO H41!!!
Thread pics up at
http://forums.corvetteforum.com/show....php?t=2066961
post #37.
Last edited by schrade; 07-18-2008 at 01:57 AM.
07-17-2008, 08:28 PM
#76
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WHERETHEHELLISZEITZ!!!!!!!!!
What size fuse do you have in socket 29? What does the cover say for 29?
Clear your codes, pull the fuse, let the motor run to about 231 or 232 for a few minutes (a few degrees over what your fan comes on at), then shut down, and check for codes.
I bet you get no H42...
What size fuse do you have in socket 29? What does the cover say for 29?
Clear your codes, pull the fuse, let the motor run to about 231 or 232 for a few minutes (a few degrees over what your fan comes on at), then shut down, and check for codes.
I bet you get no H42...
07-17-2008, 10:44 PM
#79
Melting Slicks
Good luck on finding the problem Schrade!
