Bill Curlee

Now that you have some of the broke things repaired,,,,go back and read and post the DTCs again. Post any that pop up.

Goes the scanner that you use have the capability of data logging?? Lucky is correct. Data logging will easily pin point the issue.

BC

jac1979

No the scanner that I have is very basic. The following codes were stored...

SDM U1016H
LDCM U1016H, U1096H
RDCM U1016H
RFA U1096H, U1016H

I am unaware if the dealer did any kind of diagnostic to verify the functionablity of them. Does anyone rent out tech II scanners? Or I would buy a scanner but I would like to get something that has good capabilities. Can you recommend any scanners?

No I didn't verify the repairs to the CKP with a DMM. I didn't have the service manuals with the connector pin wire routing at the time. But now that I have the manuals that probably isn't a bad idea.

Bill Curlee

i have an excellent scanner. Its an ACTRON CP 9180. I paid $140. on the Internet. I purchased it to read the DTCs on my 06 Coupe and my Jeeps.



http://www.amazon.com/Actron-CP9180-.../dp/B000KG8KB0

Just google it and you will find tons of people selling it. It test and scans a lot of sensors including LTFT and O2 sensors.

Something is going on with all those U series DTCs. Are you SURE that the door wiring harnesses are not causing an issue. Do your doors function properly (windows, lock and lights)????

Try removing the top of the STAR connector for the doors and seats. Look in the passengers foot well and to the left of the BCM. You will see TWO thin Grey connectors:



The one with FOUR wires id the one you need to disconnect. Once the top of the connector is removed, try to start the engine.

BC

tstar

Hey Bill... I have a theory on the multiple U code issue. I wonder if the memory settings being automatically activated or "easy entry" (or whatever it's called) is loading up the data bus during the time that the BCM is sending out "Are you there" requests....

Bill Curlee

Tim

That may be an issue if there is a module voltage issue. When the battery is LOW, the modules time out and if they come on like in the middle of some other modules reporting period, yep, that would be an issue.

The U series DTCs that the OP is seeing is not normal and has something to do OR is a result of the issue. I have Memory set on my car and NEVER EVER see U codes on a routine basis. Sure, there will be some when the car sits for an extended period of time and the battery is LOW charged. Under normal operating conditions, good battery, there shouldn't be any DTCs

Another theory (and I hate to just always blame something) is the ignition switch is dirty/burnt contacts and some of the modules are having "HOT in Start & Run" voltage issues. Its easy for me to check for this BUT,,,,,,some people have electronics-phobia and don't like to probe around on the fuses that supply that voltage. Hell, is easer for some to just rebuild the switch and call it a day.

Until he ISOLATES those modules on the serial buss, the juroy is still out on that prospect.

If you remotely suspect that your having a ignition switch issue,,,heres a post for YOU!

- C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html

jac1979

Ok well the windows and door locks were working yesterday but they are not working now. I tried taking off the gray cap of the connector you were talking about and start the car. No change...the car starts but still runs rough. Now that I have replaced the gray connector the door locks don't work (unlock still works), windows don't work, FOB lock/unlock doesn't work. And now there is no communication with LDCM & RDCM. When I turn the key on now I hear clicking noises in the passanger footwell area...more that usual.

jac1979

I'm trying to find those gray connectors in the service manual. What do they actually do? The gray cap on them appear to only be plastic so I'm confused as to thier purpose. Is it a point where you would plug in a high end scanner to troubleshoot problems only in those circuits?

jac1979

More info...when I hit lock on the FOB now the security system does work but the locks do not. Other thing that is weird is that the parking/reverse lights flash 6 times when you hit lock...never did that before.

jac1979

Here are some additional codes that have came up...

PCM P0102HC (because I took the air duct off to look at the throttle body during start-up)
BCM B2587H,B2592H
HVAC U1160HC

I also watched the throttle body valve during start up and when the engine is running in this poor condition. The valve opens about 1/4"...is this normal or should it be opening more at idle?

jac1979

Ok so I found someone locally with a scanner that had the ability to access the sensors. He said that the crankshaft position sensor wasn't giving an output signal. I verified the wires from the sensor to the pcm...wires are good. I think the problem is that there is no voltage present in the low voltage wire. According to the wiring diagram in the service manual low voltage is supplied by the pcm. Does anyone know if the low voltage is always there when the key is in run or start? Or does something else have to be satisfied before the low voltage will be supplied?

I'm thinking the PCM may be my problem.

Bill Curlee

Your talking about the sensor ignition feed signal. Looks like its a 12 VDC signal. There are several PCM 12 VDC inputs and all of them have to be there for it to work properly>

Check ALL of the PCM fuses and make sure you have FULL Battery voltage on ALL of the fuses. There are TWO small openings on top os all the fuses. Those are test points that you can use to test the fuse with a volt meter.

HOT AT ALL TIMES
PCM-B Minifuse #23

Hot in On and Start
PCM Minifuse #16

This is from the 98 service manual so the numbers may be different but the fuse names are always the same.

BC

jac1979

Well here is where I am at now, for whatever reason the car won't start at all now. I checked for a spark and I am not getting one. Even though I don't have a CKP DTS Code I followed the flowchart in the service manual for the P0335. With the key on and when I measure the 12 volt line of the CKP to a ground it equals the battery voltage. But when I measure the voltage between the 12 volt line to the low voltage line it is always 1.1 volts less than the battery voltage. According to the service manual both the 12 volt circuit to ground and the 12 volt circuit to low volt circuit should equal the battery voltage. The service manual says to replace the PCM if both of these do not equal the battery voltage.

I checked to make sure the PCM was getting the full battery voltage at circuit 340 going into the blue connector of the PCM immediatly prior to the blue connector...and it is. So I'm thinking this eliminates the chance of something being wrong with the ignition switch as far as for purposed of voltage supply to the pcm. Also checked the ground for the PCM which is above the starter in the engine block. It looks clean and is tight.

Bill I checked both of those fuses and they are both good. And sorry for the confussion in my previous posts, I was thinking that the low voltage line would send 5 volts when the engine wasn't running.

I have also replaced the CKP sensor and the CKP sensor as it wasn't connecting tightly. Both of which did not solve the problem. I bought a new PCM for $112 just need to get it reflashed. Hopefully that fixes the problem. Any thoughts on if my thinking is accurate?

jac1979

Ok guys go easy on me here, turns out the problem was that I had a valve spring break. And here is the result...



The fried wires on the CKP sensor led me to believe it was a timing issue. I was in the process of checking the CMP sensor when I saw a broken valve stem and realized I had major issues.

I'm thinking it's a problem related to bad valve springs in 2002 LS6's that I have read about on this forum.

I just want to know how the heck the dealer every came up with the idea that the fuel pump was bad. What are the chances that the fuel pump and a valve spring and goes through the cylinder all at the same time???

Has anyone ever changed a piston from the lower end with the engine still in the car. It looks like it is possible if you take the front cross member out to remove the oil pan according to the service manual. But is it easier to do it that way or pull the motor?

Cscokd

Bummer for sure. So sorry about the piston. I don't think you can pull the piston from the bottom but I could be wrong.