IPC working intermittently
Thanks in advance,
Damien
Have you ever had water intrusion problems?
Last edited by martysauto; Nov 19, 2014 at 10:10 PM. Reason: Correction
Last edited by Gotubch; Nov 18, 2014 at 11:56 AM.
My first guess is that the IPC is going south on you but more diagnostics are needed. Not at home to start help with diagnostics right now.
If everything else controlled by the BCM and PCM works fine it supports my IPC theory.





Heres how to read the DTCs from the drivers seat:
READING YOUR Engine Diagnostic Codes
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine. NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.
Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.
Here are some very good sites that explains the DTCs:
http://www.stengel.net/diccodes.htm
http://www.corvette-web-central.com/C5DTCcode.html
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix!!





If it were me, I would take it apart and look for obvious issues or damage. I do not know of any place that specifically repairs the module,, however, If you have an obvious place thats damaged, go to a local TV repair shop and see if they can attempt repair.
Other than replacing the entire module, your options are limited.
You can find USED modules and I "think" you can still get a new one.
Its a plug and play replacement. You will need to get the mileage set by a licensed facility that has that capability.
Check out these post:
- C5 Gage Cluster disassembly - http://forums.corvetteforum.com/c5-t...post1570380674
- C5 Gage Cluster Post - http://forums.corvetteforum.com/c5-t...post1570380878
The Best of Corvette for Corvette Enthusiasts
Here are some IPC repair shops that you could talk to. Never used any of them myself.
http://asapspeedometerrepair.com/ (Forum recommended)
http://www.instrumentclusters.com/
http://www.gminstrumentcluster.com/a...te-automotive/
http://www.sotelectronics.com/repair_gm_ins.php3
Here are some IPC repair shops that you could talk to. Never used any of them myself.
http://asapspeedometerrepair.com/ (Forum recommended)
http://www.instrumentclusters.com/
http://www.gminstrumentcluster.com/a...te-automotive/
http://www.sotelectronics.com/repair_gm_ins.php3





Bill
Thanks for all the assistance,
Damien
I think you answered in your post what I was asking of another member on my thread:
https://www.corvetteforum.com/forums...t-diagram.html
(see last post there for my question).
It appears you've bench teseted a C5 IPC before. As I thought having repaired and / or tested similar GM digital clusters (Olds Toronado 1987-89) I was expecting to at least see something indicate the supposededly working fine used IPC I got on Ebay (complete with all switches ad bezel) to do something when 12v applied to A 13, 14 and ground to B13, 15. Although th above diagram doesn't show pin 15 gnd, it is shown on the main IPC diagram and the connector pinout.
Aside from analog gauge needle deflection, should there not also be at least some llumination of LEDs, bulbs, or the DIC flashing on for a moment as well? This IPC sat in a garage on a shelf for two years (found out after I bought it and this was the seller's reasoning why it should still be working...). I also had a pungent almost putrid smell emanating from the HV metal box when I received it, had a ribbon cable that is pinched between the two white plastic housings (separating the motherboard from the IPC gauges). I'm in the process of getting my money back with Ebay's help on this. I have 35+ years as an electronic tech, same years as a journeyman electrician, and years of experience in auto electrical systems and wiring so I know how to power up an IPC and this IPC is a DOA IMO, but this guy swears it was working. However, as I allude to; "working when I removed it two years ago", does not equate to working and tested good at time of listing...







