Martyn

I just today purchased a C5 convertible, I brought it home on my trailer as I was alone and had no driver.

I have the dreaded Steering lock issue but have just ordered the bypass for that so thats taken care off.

When I got it the battery had been removed and it had been left 2 months without one connected, I dropped by the store on the way home and got me a new battery.

Ok did some reading on the codes and I found the TCM connections had been an issue to some members so I disconnected and cleansed the connections, I did a code clear and Voila perfect

Well so much for that excitement,, after starting it up to move several times (at under 2mph) the Performance reduced kicked back in and so no revs over 1500

I cleared the codes again,, it works again,, so I am after any help to point me in the right direction, I am by no means an expert but am not afraid to have a go at most anything.

Thanks in advance.

dadaroo

I don't know what you mean by TCM?

What is the voltage AT the battery? Did you make sure it was charged before you installed it? Low voltage will cause CL issues and other electronic problems in addition.

A fully charged battery should be 12.6v or more. Sounds like weak battery. Brand new batteries are not always fully charged off the shelf.

It's not 12 volts it's 12.6 because each cell is 2.1 volts.

If the battery is

12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained


Hope you ordered the LMC5 bypass. It is the only one that does not require you to undo any GM "supposed fixes". If you did not you should.

Mr. Sam


I consider the LMC5 to be the best Column Lock problem permanent fix out there. It also does not require you to “undo” any previous CL attempts to resolve this issue. Their eBay ads have a good video that shows the install at the BCM. It does not cover everything in the written instructions. So, read the instructions and also here is some extra info. In some cases, the BCM timing is off just enough to cause some issues. They make several versions and they can swap out/provide one of these if you have any issues. Their customer support is as good as it gets.

Not uncommon for people to "put the column in a pre-lock condition" and not know it and then start with the install. In other words, they started with the column lock “energized’ even if it was not actually locked yet. If not actually locked yet, it will be as soon as you turn the steering wheel after the LMC5 install. It will then remain in the locked condition until you cause the motor to unlock. It will then remain in the unlocked condition since the motor is then unpowered with the circuits disconnected.

Here is one way to prevent that if your column locks and unlocks normally:

If the CL is functioning normally you don't not need the Unlocker, merely turn the ignition ON, pull fuse #23 in the I/P fuse box, turn ignition OFF, turn the steering wheel (left and right) and verify it is unlocked. Next, disconnect the negative battery terminal, re-insert fuse #23 and continue with the install.

Also the 1999 and later C5's have a column lock relay that can be unplugged or else it will be powered and could fail and drain the battery. The LMC5 written guidance provides this info. This relay is above the BCM.

They also have a great install video in their eBay ads you need to watch.

Compliance Parts website: http://complianceparts.com/index.html

dadaroo

Here is a link that discuses both of the codes. Not at home to help further.

https://www.corvetteforum.com/forums...ease-help.html

Martyn

I ordered the following
THE ORIGINAL COLUMN LOCK BYPASS SINCE 1999

C5 Corvette Steering Column Lock Bypass
Steering column lock bypass kit for all 1997-2004 Corvettes
This bypass will eliminate the problem with the steering column locking up
The kit includes bypass box, harness and connector, instructions and everything you need to install
Also includes a 12 Volt adapter, which is necessary to disable the lock before installing the bypass box. The adapter is no longer needed after the bypass box has been installed.
Purchase now and avoid being stranded because you start your Corvette and have the steering column lock and can't turn the wheels

I assume that will do the trick, The brand new battery I charged up overnight and it is 12.8V

I believe the 2 problems I have are due to the car not having any battery in place for some time (months) so I have cleansed pretty much every contact under the hood to no avail.

I will read the link you just sent me,, thanks for helping

Martyn

TCM,, to me means Throttle control module,, its the one under the passenger fender with 2 plugs going in to it, it is piggybacked to the main computer by the looks of it

73Corvette

There is a TCM, but it's the Traction Control Module located under the PS reservoir...
The PCM Powertrain Control Module is located behind the passenger front tire/under the battery....
The BCM and the PCM are your two main players...

73Corvette

https://www.corvetteforum.com/forums...-there-is.html

Martyn

http://temp.corvetteforum.net/c5/pat...ech/frame6.jpg

Between the right hand front jack and the passenger tire is a silver module, in front of that is the black module, this is the one I am referring to

73Corvette

https://www.corvetteforum.com/forums...ac-module.html

Martyn

I just went to the store and got me a Throttle position sensor, I will fit that in the morning and reset and see what happens next,, Guys I apprecite the comments you have made very much

Martyn

I got to the TAC module yesterday amd it seemed clean and dry, however i removed both plugs and put some high quality contact cleanser on both the plug and socket and made the connection several times and then reassembled the inner fender,, it didnt change anything

dadaroo

Have you looked at the link I provided on the two codes?

I can provide the actual FSM diagnostics on each one if you want them.

Martyn

I did thank you Dadaroo,, I am waiting on the steering lock module fix first as i can only drive 2mph hahaha not much of a test at that speed and I plan to replace the TPS this morning then I am away until Sunday night but will check the butterfly also and let Yall know,, thank you so much for your input

I am using an OBD1 /2 tool Inova so its fairly advanced if you need to know any info I pull from it?

dadaroo

No, you need to be pulling the codes from the dash DIC. That way we know you can access the 325 or so possible codes from the more than a dozen modules.

If your scanner can pull underlying data such as signal or reference voltages or activate functions like a Tech 2 it might be helpful.

Martyn

I will check in a short while,, got to take back a tps as its the wrong one hahaha see that mentioned before

YomasterScott

Both codes are TPS sensor codes. Check the wiring leading to the TPS for any breaks. I had the same codes that would occur sporadically. Replaced the TPS to no avail. Turns out someone who owned the car before me had cut the original TPS connector off and wired up a new one using crappy butt connectors and taped it back up real nice. I fixed it correctly and soldered the wires up and haven't had a problem since.

BigGun

These codes are almost always found to be caused by faulty wiring or connecters.

Martyn

Thanks Guys, I have to agree,, a TPS Sensor is such a simple devise,, I changed it anyway,, cost like $22 when I got the right one,, I am just waiting on my steering lock security bypass then hopefully I am then good to go.. I have started it up several times and all appears ok for now except i cant actually go anywhere hahaha so will see,, Wednesday when I hope to have the bypass module here

Everyone who has given any input,, Thank you very much

Martyn

ok made time today to work on the vette further,, the TPS is now replaced and engine is revving well and no check engine lights etc and no codes,, I also sent away for a Column lock simulator kit,, it was a small black box with a small plug and a cigar lighter plug and another 4 pin socket,, followed the basic instructions, my steering was not ever locked so the cigar plug part I did anyway but it made no difference.

Results are now it asks to "pull key and wait 10 seconds" it said in the instructions if this occurs to remove the 3 plugs on the BCM module for several hours,, I have them all disconnected and will reconnect them in the morning,,

I dont have a good feeling about this module?

dadaroo

Did your instructions tell you how to check for GM "fixes" and if they need to be removed to install the module?

That is what is nice about the LMC5, you don't have to undo any previous attempts to correct CL issues.

If your CL module does not work then order an LMC5 as I recommended above.