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Looking for input or troubleshooting advice for my latest problem. I have a 2002 Z06.
Yesterday morning I was coming home and all of a sudden my instrument panel went dead, including the DIC display. The engine continued to run so I kept going in the hopes I would make it home. Unfortunately about 5-10 minutes later the engine cut off and the horn started blaring continuously. I coasted to the side of the road and spent 10 deafening minutes looking up the fuse panel diagram to stop the horn.
The elec seat and mirror still worked, and the steering wheel was not locked. Turning the ignition key did nothing after it had been sitting a while turned off. I managed to disconnect the battery and waited 10 minutes. Restarted, and while I had no gauge display or DIC, I made it another few miles back to my garage.
Once home I realized that water was running in to the passenger footwell and the AC drain was clogged. I disconnected the battery, removed the BCM, and fixed the clog. The inside of fuse panel was not wet but had water on outside. Same case with the BCM. The circuit board of BCM did not appear wet but I did see some charring in the area of diodes right next to one of the wire connectors. I cleaned the board with alcohol and left inside to dry. Dried out the floor/carpet and setup a fan in the car overnight.
I went through the fuse panel diagrams for both passenger footwell and under hood and checked all fuses that seem like they could affect the associated issues.
With everything dry I reconnected the BCM and then battery and replaced the horn fuse this morning.
The first time I put key in ignition and turned I saw the DIC flash Corvette and all gauge pointers swung all the way to right and then back to zero. The engine, brake, and security idiot lights all came on briefly and then go off. The car starts up and runs, the horn is NOT going off, but the gauges do not work and the DIC is dead. HUD is not operational, radio does not work, trunk switch not working, etc. The seat motors are still working.
I disconnected battery, waited and the repeated. This time gauge pointers did not move and DIC did not come on even briefly. The idiot lights did come on at startup and then go off.
When I turn off ignition the security light comes back on and stays on even after I remove the key.
So, do I have a bad BCM or might there still be another problem? What else should I be checking? Any way to be sure it’s the BCM? If it is, what is my best source for a replacement or can I have mine repaired like I tried with my ECBM years back?
Thanks for the help.
Looking for input or troubleshooting advice for my latest problem. I have a 2002 Z06.
Yesterday morning I was coming home and all of a sudden my instrument panel went dead, including the DIC display. The engine continued to run so I kept going in the hopes I would make it home. Unfortunately about 5-10 minutes later the engine cut off and the horn started blaring continuously. I coasted to the side of the road and spent 10 deafening minutes looking up the fuse panel diagram to stop the horn.
The elec seat and mirror still worked, and the steering wheel was not locked. Turning the ignition key did nothing after it had been sitting a while turned off. I managed to disconnect the battery and waited 10 minutes. Restarted, and while I had no gauge display or DIC, I made it another few miles back to my garage.
Once home I realized that water was running in to the passenger footwell and the AC drain was clogged. I disconnected the battery, removed the BCM, and fixed the clog. The inside of fuse panel was not wet but had water on outside. Same case with the BCM. The circuit board of BCM did not appear wet but I did see some charring in the area of diodes right next to one of the wire connectors. I cleaned the board with alcohol and left inside to dry. Dried out the floor/carpet and setup a fan in the car overnight.
I went through the fuse panel diagrams for both passenger footwell and under hood and checked all fuses that seem like they could affect the associated issues.
With everything dry I reconnected the BCM and then battery and replaced the horn fuse this morning.
The first time I put key in ignition and turned I saw the DIC flash Corvette and all gauge pointers swung all the way to right and then back to zero. The engine, brake, and security idiot lights all came on briefly and then go off. The car starts up and runs, the horn is NOT going off, but the gauges do not work and the DIC is dead. HUD is not operational, radio does not work, trunk switch not working, etc. The seat motors are still working.
I disconnected battery, waited and the repeated. This time gauge pointers did not move and DIC did not come on even briefly. The idiot lights did come on at startup and then go off.
When I turn off ignition the security light comes back on and stays on even after I remove the key.
So, do I have a bad BCM or might there still be another problem? What else should I be checking? Any way to be sure it’s the BCM? If it is, what is my best source for a replacement or can I have mine repaired like I tried with my ECBM years back?
Thanks for the help.
Seems to be BCM (serial data buss ) related. THE BCM IS NOT HAPPY!!
It does NOT do well with water. Do a more careful BCM Mother board inspection. Look for white corrosion between contacts and under mounted components. Use alcohol and a toothbrush to scrub off the board and re-dry. Used compressed air to make sure all water/moisture is off the board. MAKE SURE that the BCM connectors do not have water/moisture inside the connectors. Blow them out with air and dry.
Reset ALL DTCs once the BCM has been reinstalled and see where you are at. Then read the DTCs immediately if there is an issue (before you turn off the ignition).
There can be other problems causing the serial data buss to have issues. To the LEFT of the BCM are TWO thin connectors. Find the one with FOUR wires and pop the top shorting bar off the connector and see if that makes a difference This isolates the LDCM, RDCM and SCM serial data from the remaining modules.
Bill
Last edited by Bill Curlee; 02-22-2018 at 11:18 AM.
Seems to be BCM (serial data buss ) related. THE BCM IS NOT HAPPY!!
Reset ALL DTCs once the BCM has been reinstalled and see where you are at. Then read the DTCs immediately if there is an issue (before you turn off the ignition).
There can be other problems causing the serial data buss to have issues. To the LEFT of the BCM are TWO thin connectors. Find the one with FOUR wires and pop the top shorting bar off the connector and see if that makes a difference This isolates the LDCM, RDCM and SCM serial data from the remaining modules.
Bill
Thanks Bill,
A couple follow-up questions. What is “reset all DTCs”? Is that the DIC codes? If so, I can’t because I have no display. The DIC did flash Corvette when I first turned key to right but then it goes blank. It actually just did it again when I tried once more.
I also just tried removing the bar off the connector with 4 wires and it did not help. It was a repeat of the first try.
Previously I had used the compressor to blow out all the connectors and I just did again now for good measure. I just removed the BCM, and will scrub it one more time tonight and then give it another shot in the morning.
Thank you for the help.
The voltage to the IPC may be an issue. Find the Instrument Cluster FUSE and using a DC Volt Meter, test the TWO TEST SLOTS on top of the fuse to a good chassis ground. Measure each test slot to CHASSIS GROUND (with the KEY "ON") and see what you get voltage wise.
IMPORTANT!!!!!!!!!!!!! It SHOULD be 100% battery voltage but, if you are having an ignition switch issue, it could be a LOT LESS and that my friend will cause all the issues your are seeing..
Report results..
Bill
Last edited by Bill Curlee; 02-22-2018 at 02:30 PM.
Ok, I reconnected the battery. The BCM is NOT installed.
Turned key to on position. Ran a jumper cable from the ground connection near front of engine on driver side.
Voltage reads 11.88 from both test slots of the #19 fuse labeled as “instrument panel control”.
With key still “on”, voltage on meter registers 11.96 when connecting probes direct to battery terminals.
With key “off”, and hvac blower not running I get a 12+ voltage reading.
When the BCM is not in the car, and with the bar off the connector w/ 4 wires, the DIC stays on and is displaying all the errors you would expect. The gauges also seem to be functioning in this state...
Thanks
11.88 is close enough to eliminate the voltage as an issue on the IPC Fuse.
Try tht same test on all the BCM fuses. The BCM has like 4 fuses.
You will need to reinstall the BCM and then reconnect the battery.
Bill
Success!!!
I guess it needed a second scrubbing with alcohol. I didn’t spend a lot of time scrubbing the whole board the first time and had just concentrated on the area that looked a little charred. Or maybe it just needed another day for everything to dry out. Either way everything except the trunk lid release is now working, and I am getting no error codes after a complete reset. All 5 of the BCM related fuses show just a hair under 12V on both test slots.
I can hear the relay clicking when I push the trunk release. Fuse looks good. I’ll search here for diagnosing that.
Thanks so much Bill. Really appreciate the fast and detailed responses. You are a true Vette Guru.
I have my cluster, radio,windows and ac not working . I have tried ,grounds ,replacing the motherboard/bulbs(instrument cluster ) i even tried to install a used cluster. I'm totally stressing and I need help .
I have my cluster, radio,windows and ac not working . I have tried ,grounds ,replacing the motherboard/bulbs(instrument cluster ) i even tried to install a used cluster. I'm totally stressing and I need help .
Welcome to the Forum !!…looks like an easy diagnosis…looks like a bad ignition switch…all 4 of the modules you don’t have working are powered by 1 of 4 supply voltage wires from your ignition switch…you know how to use a DVOM ??…we can show you how to verify !!…also pull the codes from the DIC if you can.Would be best to start a NEW thread instead of hijacking this one…a lot easier to get help and for us to navigate here !!
Welcome to the Forum !!…looks like an easy diagnosis…looks like a bad ignition switch…all 4 of the modules you don’t have working are powered by 1 of 4 supply voltage wires from your ignition switch…you know how to use a DVOM ??…we can show you how to verify !!…also pull the codes from the DIC if you can.Would be best to start a NEW thread instead of hijacking this one…a lot easier to get help and for us to navigate here !!
Im new to the forum and I don't know how to star a new thread or use a dvom . If It is the ignition switch,what should I do next ? Also the dic displays codes, however; it follows with "no comm" next to every code.
Thank you
Kevin
Last edited by Kevin7seven; 09-07-2021 at 07:54 PM.
Don’t worry about starting a new thread and don’t worry about not knowing how to use a DVOM…just take the car to your mechanic and have him verify that it’s the switch and let him change it !!…if it’s not the switch but a serial data bus issue (you said there were all no comms) hopefully he knows how to diagnose that…are the no comms just the AC, IPC, Radio and windows ??…one of the cars modules is causing the problem …either the module is bad or the module lost a power or ground to it !!
Don’t worry about starting a new thread and don’t worry about not knowing how to use a DVOM…just take the car to your mechanic and have him verify that it’s the switch and let him change it !!…if it’s not the switch but a serial data bus issue (you said there were all no comms) hopefully he knows how to diagnose that…are the no comms just the AC, IPC, Radio and windows ??…one of the cars modules is causing the problem …either the module is bad or the module lost a power or ground to it !!
All dic codes display "no comm " i don't know anyone but ill see who I can find .
best regards
Last edited by Kevin7seven; 09-07-2021 at 08:56 PM.
Beverly Hills ???…you should be driving a Ferrari…LOL. !!…I’m sure there you many diagnostic shops in LA…this shop is your best bet !!..if they can’t diagnose it have them contact us here at the Forum !!
Beverly Hills ???…you should be driving a Ferrari…LOL. !!…I’m sure there you many diagnostic shops in LA…this shop is your best bet !!..if they can’t diagnose it have them contact us here at the Forum !!
if I get the ignition switch replaced would it require reprogramming?
Last edited by Kevin7seven; 09-09-2021 at 09:24 PM.
MMMM ??…I was 99.9% sure the switch would have fixed it…is your mechanic a diagnostician or just a parts changer ??..see if you have any U codes present…may be a serial data bus issue…don’t know if your guy will be able to diagnose this…a lot of times we have issues with the Driver Door Module wiring…open the drivers door and shake that rubber boot on the door…see if it starts…a video is enclosed !!
02-22-2018, 10:43 AM
Dead instrument panel, DIC, & other issues
