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View Full Version : IPC speedo, tach DIC codes help


O1Z06
April 4th, 2015, 05:11 AM
Hi all, I have been having a bit of trouble recently after I set a reduced engine power after modifying the ETC traction control table. I immediately set the values back to original and reflashed the OS. I also have roadrunner so that was an easy job.

I am still having these codes showing up as history and when accelerating pretty hard I did see my speedo go to 200 mph for a split second and then the TC kicked in but it didn't feel normal but more like the pedal went dead until I released it.

Where should I start? Check all the connections? There a lot of them. Would the roadrunner coin battery going bad do this?

Codes are:
B0516
B0521
U1096

http://tapatalk.imageshack.com/v2/15/04/04/488bd8835232c66e164e9121e1972b2f.jpg
O1Z06
April 5th, 2015, 12:08 PM
What is node DSW?
joecar
April 6th, 2015, 01:51 AM
You car is a 2001-2004 Corvette...?
joecar
April 6th, 2015, 01:51 AM
( I thought RR battery was just to keep it alive when not in car or when USB not connected...? )
O1Z06
April 6th, 2015, 12:24 PM
Hi Joe, yes it's an 01-04.

I would think the RR battery is there for like you said to keep the volatile RAM from being lost. Things like crank reluctor signature, vin, vats, and of course the tune. I recall reading a while back that Mr. Prick had to do the crank relearn a lot after disconnecting the main power.

But I think I found my problem. I started looking at schematics for all common modules where I had a problem. IPC, RFA (wireless key fob called DSW in OBDII scan tool) and PCM. Found a ground that is scared by 4 wires from the PCM called G106. It's above the starter bolted to the block.

The ground bolt was loose which would explain the interment loss of comms. Have not tried driving it yet but all signs point to that being the problem.

What are the 4 PCM ground here for?
http://tapatalk.imageshack.com/v2/15/04/06/2e642d11b6499e2a96fdd48f9a53d626.jpg
joecar
April 7th, 2015, 03:11 AM
Ah, DSW = RFA key fob module (learn something everyday).

G106 looks to be important... the PCM has various internal circuits each of which requires a ground (I don't know exactly, but probably OBD2 serial bus comms uses that ground).

Probably should check the other grounds while you're at it (don't forget the one behind the LHS head).