Ok, so I have searched long and hard about this to see if I could figure it out, but I am not the greatest with electrical so I need your help.

I have been fortunate enough to have lots of rain water to leak into my car through the great aged weather stripping, and now I am having issues starting my car. Originally it would be fine after it dried out, but now I can only start by rolling (which hasnt bothered me quite yet because I am in the middle of maintenance and my car is off the road). I am almost set to get it back in driving mode so I need some help fixing this issue. I am thinking it is a grounding issue but I really have no idea.... When i push my clutch in it just wont start.

I tried tracing the wires from where they clip in and they meet up with a bunch of other wires and run under the seat somewhere. Is there a main ground or what? I am lost....

Thanks

Thomas

 

i wouldnt think you would be able to push start the car if the clutch switch was bad.

 

Yikes. Time to evaluate the passenger footwell for moisture....especially the BCM and TDR. Pull your codes.

 

Why not? It just energizes the TDR.

 

Before you get too lost,, heres a schematic that you need to review. Learn it,, use it. Without reading the DTCs as LUCKY recommended and without this schematic,, and doing some basic troubleshooting,,,, break out the wallet and dump all the cash and credit cars on the parts counter and tell them to take what ever they want!



The Theft Deterrent Realy is the heart of the starting circuit. Check the power and fuses and then inputs and outputs of the TDR!

 

You may need this also!

READING YOUR Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and 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 module. ( 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 types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present 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 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 RESET 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. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.

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 read the DTCs while the engine is running. If you turn the engine OFF and then back ON, that can clear some DTCs that may be important with identifying a problem. One example is a Misfire DTC (p-0300) If the engine is shut down, the DTC will clear.

These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs

Here are some very good sites that explain what DTC mean:

http://www.gearchatter.com/viewtopic11755.php

http://www.obd-codes.com/trouble_cod...d-ii-codes.php

Make sure to include the H or C suffix when you post your DTCs!!

 

wow, crap, thanks for all the help guys! Bill thanks for taking the time to write out all of that information. Looks like it's back to school mode to learn all this stuff and buy a service manual. I wish this was a bang on the juke box like the fonzie problem.

 

So here is the update. I checked all my DTC's and there were no current or none that had to do with it starting unless I missed something, but no new codes are coming up when I try to start it. I found this link that is a TON of help for anyone having starter issues http://www.c5help.com/c5_no_start.htm I jumped my safety switch just to rule that out, I checked my fuses...all good, I am not sure how to jump the TDR to see if that is the issue so I am thinking of just buying a new one (they are cheap), I have not yet checked my starter or solenoid, but will when I replace my radiator this weekend.

The interesting thing is that right after I cleared my codes and tried to start it, it turned over but I did not have enough juice in my battery for it to start, so I hooked the charger up to it and nothing. This tells me that it is definitely an intermittent issue since once every blue moon if i try it, it turns over. Any thoughts Bill? I am really hoping it is anything but my BCM...i hear they are expensive.

 

Interestingly enough, the link you posted, tells you how to do exactly that.

 

I just noticed that...haha I am going to do it right now. I got confused and thought it meant something like jumping the relay...I didnt notice the CONNECTOR part. My bad. However I am very pessimistic about this...I have a troubling feeling that the TDR is not the issue. Oh how I hope I'm wrong.

 

Jumped the TDR like it said...nothing. ugh that rules out one more thing, which means im that much closer to it being a BCM issue.

 

Not sure how you arrive at that conclusion....UNLESS...you have an issue that is not understood....because you have not posted your codes. The BCM controls the TDR. If you jumpered the TDR, and it still does not start, the BCM is out of the picture. If you do not use a meter, and start doing voltage/ground checks(using the schematic provided by Bill), or the website you posted.......you will be chasing your tail forever.

 

You really need a multimeter. Make sure that you have battery voltage on the RED WIRE all the time. If you do,,,,,,,,,,,, and jumper the RED and PURPLE wire together,, you have a solenoud/starter issue.

If you rap the starter with a hammer while your attempting to crank the engine,,, and it starts,, you most likely have a solenoid issue..

BC

 

1000% correct. If you have a confirmed 12vdc (battery voltage on the red wire) and jump the RED to PURPLE wire,,, the starter/solenoid should work and start the engine. PERIOD! If not,, you have a purple wire or solenoid/starter issue!

 

OK.....this is important. I push started my car to drive it around...and then my belt blew (irrelevant) but after I shut it off in the street...I tried starting it...and it started...I did this twice and it started both times. There is something in the troubleshooting link about the BCM going into sleep mode and not coming out when you insert the key. It almost sounds like this issue but it also says that the hatch release on the fob wont work but mine does. I waited over 30 minutes to see if it started again and checked to see if my key fob worked and everything. It started, soooo I am starting to think it is a starter issue...My mechanic friend thinks it is probably just the starter going bad or corroded wiring or something on the starter, but I will check that when I get under the car.

 

I literally know nothing about electrical...so i assume already I am wrong. i am just trying to go off of that link I posted, but I have no idea of what it all means. I was an economics major, they dont teach us electrical stuff. When I do my radiator this week or weekend, my friend is going to help me check out everything. I will update when I know more.

 

So if anyone still cares, I got everything resolved. Swapped my starter and now I'm rockin and rollin.