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Dose anyone have any experience with this? My car is in the shop now and I'm being told the connector has corrosion and the ECU is bad.
It's a 97 and I think the computers on 97 & 98 are different from the rest of the C5's, I did find a replacement ECU but not sure if that's the best way to go.
I had a link to a website (but lost it) that had a upgrade kit with a ECU and wiring harness.
I'm hoping some of you have already been through this and can give me some advice.
Thanks
YES, the 97 & 98 PCMs are different, RARE and EXPENSIVE!
Don't understand why the shop says its bad. Unless the case of the old PCM is corroded through or the actual PCM (that's what its called in the C5) connectors are damaged, it should be fine. If you read the C5 DTCs, it will tell you if there is an issue with the PCM.
What are the symptoms, what does the car NOT do and what DTCs are you seeing for the PCM and the rest of the modules??
PS,,,, You can read the Cars DTC using the cars IPC. They are displayed in the IPC in the DIC (see procedure at bottom of page):
Not saying that your shop is wrong but, make sure that you get your OLD PCM back if they replace it and make sure that the replacement PCM fixes your issues 100%. Some shops can fix a simple issue, say the PCM is bad, replace it and then sell yours. Just saying!
Some repair places that sell PCMs can program the new PCM to you VIN so it works just like your old one. (PLUG AND PLAY) IF,,,,,,,, You have a custom tune in the old PCM, it will be GONE if you purchase a new PCM.
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.
My car will cut off and all these codes will come up, if I clear all codes it will run but has a hesitation when I first take off but then the hesitation clears up. Then it doesn’t take long and will cut off again. Clear codes and repeat.
10-PCM P0101 Mass Air Flow (MAF) System Performance - C P1571 ASR Desired Torque - H C
28 -TCS C1225 RF Excessive Wheel Speed Variation - H C1277 Requested Torque Signal CKT Malfunction - C
40 – BCM B0432 Rear Defogger Relay Circuit - H C
A0-LDCM B2206 Right Window Up Switch Fault - H U1064 Loss of Communications with BCM - H
A1-RDCM U1064 Loss of Communications with BCM - H
I did replace the MAF before I took it to the shop, the guy that owns the shop is a long time friend that is just trying to help me out, the computer may not be bad it could be in the connector but one of the pins on the computer is messed up from the corrosion from what he told me. Thanks
Now I'm THINKING and that can be VERY dangerous but when you are saying the car "cuts off" you mean you're driving and complete shutdown ??...with the 1571/1277 and 0101 I think we are losing the 5 volt ref. which comes from an internal regulator within the PCM (see pics)….trying to figure out how the BCM and EBCM comes into play here...I'm thinking maybe another bad ignition switch...see what your battery voltage is and then turn the key ON and see what the "voltage" reading is on your DIC...if the battery is 12 volts and you read 6 volts or something a lot less than 12 you most likely have an ignition switch issue...JUST SPECULATING !!...might be a good idea to check ALL the PCM power and grounds...this could be an issue also...while you have the key ON remove the connector from the MAF sensor and see if you have 5 volts on the YELLOW wire...that is a 5 volt reference...at least we will know if the PCM is ALIVE !!…"IT'S ALIVE" !!...the 5 volt ref. is the MOST IMPORTANT voltage in the car...its life blood !!!...trying to figure out the BCM "no comms"...MMM ??...oh, this wiring is based on an '01.
Need to Replace my ECU
