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Ok gang, got a 1992 6spd. I have fuel pressure, I have spark, I have injector pulse one time when cranking then no pulse,. Both injector wires show positive with no ground. I understand on this year ecm sends ground after talking to ccm.
I got good ohms on all injectors.
No codes in ecm but cant check ccm codes because lcd dont work on cluster.
the key part of vats has been deleted, ccm still has vats and that's where I think issue is, pulled it out and apart but dont look bad from naked eye., tapped on it while starting no luck.
grounds have been cleaned and checked.
Dont have fsm at the moment to get wire diagram for ccm and ecm.
Any ideas before I just carburetate this thing lol thanks in advance
meaning no backlight (like when switched off) or weird data displayed ?
Is your "SYS" light blinking ?
Some extract fromt the FSM :
Unlike other vehicle electronic systems, such as
ECM, SIR, etc. There no specific "CCM" lamp to indicate a malfunction. A DTC-setting malfunction in
any of the CCM-monitored systems is indicated by
“SYS” (SYSTEM ERROR) flashing in the instrument
cluster trip monitor. If a malfunction does not recur
within 100 ignition cycles the CCM will automatically
clear the DTC.
The “SYS” indicator will flash 3 times every 15
seconds while a current-DTC malfunction is present.
An exception to the “SYS” malfunction indicator is
that PASS-Key® malfunctions (DTCs 51-53) will be
indicated by the “SECURITY” lamp being illuminated
without the “SYS” indicator flashing. If there is a
Fuel Enable Data Stream (FEDS) malfunction (DTC
54), the “SECURITY” indicator and “SYS” indicator
will flash together, to illustrate that the problem
condition affects vehicle security.
meaning no backlight (like when switched off) or weird data displayed ?
Is your "SYS" light blinking ?
Some extract fromt the FSM :
Unlike other vehicle electronic systems, such as
ECM, SIR, etc. There no specific "CCM" lamp to indicate a malfunction. A DTC-setting malfunction in
any of the CCM-monitored systems is indicated by
“SYS” (SYSTEM ERROR) flashing in the instrument
cluster trip monitor. If a malfunction does not recur
within 100 ignition cycles the CCM will automatically
clear the DTC.
The “SYS” indicator will flash 3 times every 15
seconds while a current-DTC malfunction is present.
An exception to the “SYS” malfunction indicator is
that PASS-Key® malfunctions (DTCs 51-53) will be
indicated by the “SECURITY” lamp being illuminated
without the “SYS” indicator flashing. If there is a
Fuel Enable Data Stream (FEDS) malfunction (DTC
54), the “SECURITY” indicator and “SYS” indicator
will flash together, to illustrate that the problem
condition affects vehicle security.
Lcd has backlight but no readings whatsoever, not even fuel. Just orange light.
Don't see no SYS or security light ever, bulbs maybe pulled as the check engine light bulb was pulled when got car., haven't got to pull cluster yet.
Ok, seems that the CCM does not manage to drive the LCD at all. The orange backlight only tells you that the cluster is properly supplied by the ignition voltage.
I would try to check if the SYS bulb is in its socket as it will tell you if CCM DTCs are available. (not which one though...). I strongly think that there are some active DTCs.
Having missing DIC bulbs is never a good sign. Any good history on the car or previous owner ?
I don't know if there are other available ways to retrieve CCM DTCs when the LCD is not responsive. Maybe other forum user's can comment on that.
Having absolutely no LCD response is pointing toward a CCM or CCM harness issue.
Are the rest of the functions (undependant from the LCD) managed by the CCM functionnal (courtesy lights when you open the doors, PKE, alarm, dimming interior lights) ?
Ok, seems that the CCM does not manage to drive the LCD at all. The orange backlight only tells you that the cluster is properly supplied by the ignition voltage.
I would try to check if the SYS bulb is in its socket as it will tell you if CCM DTCs are available. (not which one though...). I strongly think that there are some active DTCs.
Having missing DIC bulbs is never a good sign. Any good history on the car or previous owner ?
I don't know if there are other available ways to retrieve CCM DTCs when the LCD is not responsive. Maybe other forum user's can comment on that.
Having absolutely no LCD response is pointing toward a CCM or CCM harness issue.
Are the rest of the functions (undependant from the LCD) managed by the CCM functionnal (courtesy lights when you open the doors, PKE, alarm, dimming interior lights) ?
yea I'm sure there is ccm codes , and no alarm working, no courtesy lights etc. Previous owner not took care of car..
work done
Ecm was redone..
New icm
New coil.new injectors.
New fuEl pump
New opti
New heat sink.
down to no injector pulse after intial pulse. Tested with noid light.. also both sides of injector wires 12v. Nk ground coming. Tested wires one at a time then tested with all injectors unplugged to make sure not a bad batch.
really considering going carburetor since 92 is so hard on ecms, ccm, and such pricewise and availability wise.
I would try to check if the sys bulb is in its socket as it will tell you if CCM DTCs are available
The SYS message is not a " bulb". It is in the LCD display. The OP won't see the SYS message if the LCD doesn't work.
However, he suspects the VATS. The SECURITY light is a bulb. It should flash with a door open, with the key in OFF. If SECURITY is solid-ON with the key in RUN, the system is in an active VATS shut-down.
The 92 ECM is known to have issues that affect the ECM/CCM 'handshake' that is required for fuel injector activation. If the SECURITY light is NOT solid-on with the key in run, I would suspect the ECM as being the problem long before the CCM.[/b]
The SYS message is not a " bulb". It is in the LCD display
, you're absolutely right my bad !
However, having absolutely no basic functions which are normally managed by the CCM (courtesy light, UTD...) is concerning as they normally operate without passing the VATS step or password exchange routing with the ECM, what do you think IHBD ?
I also agree with you regarding the "SECURITY LIGHT", how does it behave Vetteman ?
However, having absolutely no basic functions which are normally managed by the CCM (courtesy light, UTD...) is concerning as they normally operate without passing the VATS step or password exchange routing with the ECM, what do you think IHBD ?
I also agree with you regarding the "SECURITY LIGHT", how does it behave Vetteman ?
no security light at all, going pull cluster tonight and see if bulb is in
No worries, you car, your choice. I can't argue with the fact that if your CCM is really cooked, it's a PITA to find a new one and code your VIN / Mileage in it.
I have no other tests in mind than doing a quick CCM swap if you find one.
Eventually one, do you have the possiblity to measure the ALDL voltage ? (5V). Pin M of the diagnotic connector. to see if your communication line is hard shorted to ground or battery.
You also said that you pulled the CCM out and opened it right ? Sure you didn't see anything weird (burn chips, traces ?)
Maybe the other forum user (IHBD) has more ideas to propose.
No worries, you car, your choice. I can't argue with the fact that if your CCM is really cooked, it's a PITA to find a new one and code your VIN / Mileage in it.
I have no other tests in mind than doing a quick CCM swap if you find one.
Eventually one, do you have the possiblity to measure the ALDL voltage ? (5V). Pin M of the diagnotic connector. to see if your communication line is hard shorted to ground or battery.
You also said that you pulled the CCM out and opened it right ? Sure you didn't see anything weird (burn chips, traces ?)
Maybe the other forum user (IHBD) has more ideas to propose.
yep I pulled ccm didn't see anything out the ordinary on board, is a little spot on case looks like either burn or rust. Will definitely check terminal m. And report
First, is your battery voltage holding over time ?
Here you find the power requirement of the CCM :
The idea would be to check that these currents are in the expected range.
To do so, you can use your multimeter in current mode, select at least a 10A range first and use lower ranges when measuring to increase the reading accuracy, stick the multimeter measurement leads in the fuse IP panel instead of the CCM fuses, all of them, one by one. Or directly between the positive battery terminal lead and the positive car lead (do not attempt to start the car in such conditions, fireworks guaranteed). This should tell us if your CCM is drawing an abnormaly high amount of current or absolutely nothing, the minimum being around 15mA in sleep mode.
No worries, you car, your choice. I can't argue with the fact that if your CCM is really cooked, it's a PITA to find a new one and code your VIN / Mileage in it.
He can have a replacement in his hands in two weeks, maybe even less, programmed to his VIN and key code and with appropriate mileage. It would be best if data is retrievable from the current CCM.
Originally Posted by RSLyrick
I have no other tests in mind than doing a quick CCM swap if you find one.
This is where having access to a Tech1 or Tech2 comes in handy.
@Vetteman1939 In a previous thread about your cluster, you said you worked at a GM dealership. So you have access to all the schematics and troubleshooting diagrams. I would also expect somebody in your service department to have a Tech2. Beg to borrow and buy them lunch.
He can have a replacement in his hands in two weeks, maybe even less, programmed to his VIN and key code and with appropriate mileage. It would be best if data is retrievable from the current CCM.
Yep, I know it's feasible. I would expect the guys who are preparing a >100 miles CCM to ask for some proof of the current car mileage, what if the CCM is cooked with no EEPROM reading, no LCD running, then it becomes complex. Do you still offer a CCM prog in such scenarios ?
Or maybe GM dealership still offer such kind of the service ?
Ccm/vats issue.
