Hey all!

just looked at a 1999 c5 Vert. Always wanted a c5. This one is a little rough but a good price. 180k but won’t accelerate over 3mph. Gentleman said it had the column lock recall down, and also had the column lock bypass installed. I quickly looked but couldn’t find the answer. The car now with the recall done and column lock bypass done won’t go over 3mph. He said a mechanic said the body control module was bad but it certainly didn’t look like a certified type mechanic.

Any idea if you trust the mechanic or any tips moving forward? Is there a workaround or would you trust the accuracy that it needs the module l. Also, how expensive would the module be?

 

Google the procedure for reading out the trouble codes on the Driver Information Center screen on the car and proceed from there. Good starting point

 

Make sure the LMC5 (column lock bypass) was done and done properly. Also, make sure the battery is fully charged. I'm fairly certain that one of those two things is the cause of your problem. If you take the cover off the body control module in the passenger footwell, it is obvious if the LMC5 is installed. Do a google search for an image of what it looks like. a dead giveaway is a ground wire running to the bottom of the BCM.

 

If the column lock fails, the car is restricted from going over 3 MPH. It isn't the BCM.
Find a local Corvette (C5) expert, they'll help you. It could; be as simple as a low battery.

 

Pick this up from Amazon and your problem will be solved !!

 

The LMC5 module will help.

And moving this to C5 Tech.

 

First check the batter to see how many volts it puts out with the engine off, using a VOM you should see 12.5V or better. If not the low voltage may start the car but it will play havoc to the engine computers. I had the same problem you have and it was the battery, I replace it with a fresh one (old one was putting out 12.3V) and it would start. I then changed the 2mph fuel cutoff speed to 256 mph and have not had a problem since. Also, some have mentioned an older column lock system might fail and cause the same problem. Once everything is working you should remove the old Column lock devise and install the LMC5 bypass and never have to look back.

 

Great info here! How did you change the fuel cutoff from 2mph to 256mph? That seems like it would solve a lot. I’m going to see what I can do pricewose on the car and see if I can take it home. It’s a little rough and some miles but the top is 3 years old, the wheels/tires are brand new, brakes are new. Some TLC and it could be a great weekend car

 

Use the FAULT as a price reduction point.

Once you get the right price on the car, first try this. FULLY CHARGE THE BATTERY. Clear all the DTCs using the cars DTC reading system. Then see if you see the PULL KEY WAIT 10 SECONDS message in the DIC.

That is the sure sign that you are in the column lock fault mode.

If you charge the battery clear the DTC and everything is good, GET the LMC5 and get it installed. Have that battery fully tested to insure that it 100% and make sure that you don't have any parasitic current draws that kill the battery over night.

READING YOUR C5 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.



NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.

WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.



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!!



NOTE!!! Start the car and let it idle. Then take it for a drive and cause the problem to occur. When you return home pull the codes BEFORE you shut off the engine.


Do NOT discount the codes with the H following them. They can provide an audit trail for issues going on with the car. They ARE important in diagnosing problems.

Post ALL the codes that you pull with the engine running..........

Some codes go away WITHOUT setting an H code when you shut the engine off. I suspect you will have several codes that will show C or HC that do NOT show when the engine is turned off.

 

Dealt with this issue since like a week after owning my 02 Z06.

Long story short, I bought an LMC5 and installed it with the optional brown wire step. It fixed the steering wheel lock issue, but my car would still occasionally and randomly shut off at 2mph. If it goes over, it will drive fine the entire time until I remove the key and restart the car. Then I was spinning the dice again.

During the shut-off's, I would never get any message on the DIC. It just shuts off as if I didn't know how to drive stick.

I kept in touch with the owner of LMC5 for troubleshooting and was even sent a replacement LMC5 which still did not solve the issue. After exhausting all efforts, we came to the conclusion that my BCM and/or PCM was likely corrupt. Very, very few documented issues of this being the case, my online research shows. I was one of the lucky ones.

I decided to just bite the bullet and pay a performance shop that uses HP Tuners to tune the 2mph cut off to 256 mph (you can't turn it off completely and 256 is the max setting, essentially disabling it). This was also the final remedy for the one or two other people I found online with the same issue as mine. While the tuner was in there, I also got him to lower the radiator fan activation temps by 10 degrees across the board.

Car hasn't skipped a beat since.