I have a 2002 Z06 with a problem that started last week. I was driving and lost the following systems: instrument cluster(IPC), radio, air cond.,LDCM,RDCM,,SCM,SDH,and RFA.I also had a message- reduced engine mode with service traction control & active handling ,but the car drove normally with no loss in power.I took the car to my mechanic and he determined that the BCM was bad. He placed a new BCM, but had a problem.The car would start for a few seconds then die. Thinking that the BCM was bad, he replaced it with another one, but had the same problem starting the car.Is there something he needs to do with the new BCM ?

 

What were the DTC codes. The presence of DTCs that begin with "U" indicates some other module is not communicating . The lack of communication may be due to a partial or total malfunction of the class 2 serial data circuit . Does the scan tool commincate with the BCM?

 

The new BCM must be programmed. The new one has no clue as to which RPO codes your car has (or does not have).

This "mechanic" person thinks all he has to do is remove the old unit and mount up the new one? Really??

 

BCM is bad ? Sounds like

 

TCS:C1221H, C1222H,C1226H,C1248H, C1278H, U1301H
BCM1225H,U1069H,U1016H, B0507H
IPC: U1225H, U1016H, U1064H, U1040H, U1176H, U1160H
PCM: P1631H,P1125H, P1281H P1626H
RDCM,SCM, RFA,SCM: All have serial data line malfunction.

I don't know if scan tool communicated w/ BCM. How do you program the new BCM and how is the serial data line malfunction fixed? Thanks for the quick responses. John

 

Check with your GM dealer. I'm fairly certain you may need to bring your car to them for it to be programmed via their tech terminal. Check with them to be sure. Maybe you can take the new BCM and proof of ownership of vehicle, but I'm thinking they will need to plug into the ALDL port under the dash. Check with them. Btw, any GM dealership should be able to do this. It does not have to be strictly a Chevrolet dealership.

HTH

 

Expensive Lesson in Mechanic EASTER EGGING for a repair. You can do a BCM PCM Sync procedure to get the car to RUN. You need a GM Tech II to program the RPO Codes that you have.

BCM/PCM RELEARN PROCEDURE


You will need to conduct the PCM/BCM relearn process. This matches their handshake ID's and allows them to talk to each other.

Do this before you worry about VATS issues:

1. Turn on the key for 11 minutes.
2 Turn off the key for 30 seconds.
3. Repeat 1&2 two more times.
4. Turn on the key for 30 seconds.

The car should start and run with the new BCM. Good luck and report back on your progress.
Shirl
SD Racing Enterprises
Aguila, AZ
Coutersy of MrEracer


This will sync the PCM to the New BCM but all of your RPO options will not be retained. You will need a TECH II to program them into the new BCM.

Bill Curlee


Get your old BCM back.. Its still GOOD!

BC

 

I'm wondering if this mechanic person "diagnosed" this due to any water on the floorboard issues. We don't know the history of the car.

Btw, Shirl is a great guy with some good tips but he can't put a shifter back in straight. He put mine in 180* out. He was in a hurry I guess. Honest mistake.

 

Thanks for responses. I did remove the accordian tube on driver's side and was able to get LDCM to work.Let me give you the history on the car. The car went into reduced eng. mode w/message to service traction control & active handling at 1400 miles (currently: 44,500 miles).Took to dealership for repair. Fix:change App. sensor. Drove car 5 miles and car went into reduced eng. mode. took back to dealer. They found that my car had the wrong battery and it had leaked acid onto Tac mod. and wiring. They replaced the battery, Tac mod.and circuit # 1274( tan wire), #1262(light blue wire), and #1272(purple wire) from the app. sensor to the Tac mod. after checking power & ground fluctuations while cranking with no problems found. I had no more problems until 18,000 miles. Car went into reduced eng. mode w/service TC & AH ( codes: P1125H, P1285H). The Tac module was replaced. I had the same problem at 22,000 miles.Took back to dealer and no problems were found. Back at 28,000 miles for same problem (codes:P1125 & P1281H) They replaced the accelerator pedal assembly. Back at 32,000 miles (P1125H & P1281H). They checked the circuitry terminal tension for entire throttle system and found no problems.Same problem at 35,000 miles (P1125H, P1280H, P1281H). They removed the AH module & computer . Disassembled computer, tightened the circuit mounting screws, checked and cleaned all plugs, pins & wires, checked power distribution & fuse box with no problems found. Back at 40,000 miles(P1125H). They tightened female connections at gas pedal plug & AH mod,throttle control motor and mass air flow sensor. Problem continued. Took car back at 41,000 miles. Gas pedal assemb. replaced. This solved problem for 2,500 miles. The problem continues today. The problem happens under all driving conditions & at various speeds. When it fails I have to pull over and restart the car 10-20 times until the mess. clears. The check eng. light remains lit for awhile but the car drives normally. Any thoughts on this headache?

 

Next time it happens see if you can just enter Diagnostics mode on the fly (dont become distracted and crash) and clear the displayed PCM DTC's and see if it will clear Reduced Power Mode that way.

Had the same issue on my 98 Coupe and I was so good at clearing the DTCs that I would hardly loose any speed.

 

My steering column on my 2002 z06 locked this morning with mess. to service steering column. Is there anything I can do or should I have it towed to the dealer? Thanks, John