My 2002 Z06 has 12,000 miles on it and an intermittent electrical problem. The car runs great but at times loses power to the doors and the dash panel gauges and radio. Among the DIC messages I’ve noticed the following:

• service active handling
• service ABS system
• check gauges
• reduced engine power
• Remove key wait 10 seconds
• security light on

(* note the EBCM was repaired by ABS fixers last year and all seemed well for about 300 miles. Prior to that it had been acting up much more often.)

Here is the list of codes I found now. None of them are current.

10PCM - p1626h

28TCS - u1301h, c1214h

40BCM - u1255h, u1096h, u1016h

58SDM - u1301h

60 IPC - u1255h, u1016h, u1064h, u1040h,
u1088h, u1176h, u1160h

80radio - u1064h, u1016h, u1096h

99HVAC - u1064h, u1096h, u1160h, u1255h

ADLDCM - u1064h

AIRDCM - u1064h

A6SCM - u1300h, u1255h

BO RFA - u1255h, u1064h, u1016h

I’ve searched my manual, and found almost all of these codes are for loss of communication with the exception of:

- u1300 high voltage on the class2 serial data circuit

- u1301 Low voltage on the class2 serial data circuit

-P1626 Theft deterrent fuel enable signal lost

Also note that the driver side power door lock hasn’t worked since I’ve owned the car.

I did check the chassis ground near the battery and it looked perfect.

Chevy dealer says diagnostic testing is $150 per hour but no idea how long it might take to pinpoint the problem. Does a dealership or other professional shop have special diagnostic tools that could better pinpoint where to look? Brandon at EBS fixers suggested, replacing the ignition switch, clearing the codes and going from there. Any suggestions from other knowledgeable folks would be greatly appreciated.

 

Forget about a Dealership diagnosing it..they’re idiots !!…the thing they are missing is ability…erase all those history DTC’s and when the car is running and loses power to those modules take your DVOM and place one lead on battery positive and other lead on BTSIBU Fuse 21 (either test point) and see what the voltage drop is…there are other fuses but just use this one…you should read around 0.2 volts or so…if you see 1 volt or more (0.5 volts is max) you have an excess voltage drop across the ignition switch…there is an orange wire out of the switch which feeds the radio, both door modules and IPC and other circuits…the BCM is also part of this circuit which you have a no comm with…all of the fuses related to these circuits are in the IP Fuseblock.

 

Thanks for the info- I will check that out the next time it acts up.
I would be happy if it is nothing more than the ignition switch
if not… I’ll be baaack 😎

 

Check the state of your battery too. These cars do weird things when the battery is marginal or has a loose connection.

 

SteveWI, I think I'm in the same boat as you, showing all the same codes and warnings while still running well. Still working through the issue myself, but I can lyk what I've already tried!

I also recently fixed the EBCM, which cleared the C1214 code, but didn't help otherwise. I've got a LMC5 steering column lock repair module installed, but a loose battery terminal connection damaged IP fuse 23, causing the car to display "check steering column lock" again. replacing that fuse cleared that warning but again didn't help with the full suite of codes. I see you checked the chassis ground near the battery, my next plan was going to be checking all the chassis grounds I could find. I'm thinking chassis grounds because the DTC and dashboard response seems similar to what Bill Curlee starts the following thread with:
https://www.corvetteforum.com/forums...tion-long.html

Keep in touch with your findings!

 

.......dealers are idiots.....Thats been my experience. Sad, but true. Most of todays "technicians" are usually parts changers. If you find a true mechanic/diagnostics person, you'll replace Lou Gehrig as the luckiest man on the face of the earth!!

 

Mike, not “usually” are parts changers…ARE parts changers !!

 

Contact your local Corvette club for recommended shops that can sort out C5 electrical problems. JMHO.