C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

lmc5 issues

Thread Tools
 
Search this Thread
 
Old Jan 20, 2022 | 05:05 PM
  #1  
Justin Raney's Avatar
Justin Raney
Thread Starter
Melting Slicks
 
Joined: Apr 2021
Posts: 2,189
Likes: 82
Default lmc5 issues

i just installed this 5 months ago after having the pull key wait 10 seconds and after having installing it it still does the "pull key wait 10 seconds" or "steering column lock" with the 2mph fuel cut. According to the instructions i did it correctly 1st orange wire and 3rd purple wire for the lower connector. The 2nd green wire on the top connector and lower 3rd green wire diagonal on the botton side just next to the top green wire that is replaced. Can anyone tell me why im having these issues. I feel it will kill the starter as it does this often. Does anyone know why it does this after installing the lmc5? I did remove the correct relay above the bcm as in the instructions. I just checked to make sure it was installed correctly and the 4 wires removed are the orange, purple. light green and dark green according to the module sticker itself. I posted pictures to show it was done correctly. I cut the brown wire loop and installed the caps whatever that does. I think getting it tuned can turn that off or raise the mph but would still read the pull key wait 10 seconds message without the fuel cut.






Reply
Old Jan 20, 2022 | 08:23 PM
  #2  
Johnny Hardcore's Avatar
Johnny Hardcore
Melting Slicks
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
Default

Hard to see anything in your photos.
Try giving Rich a call at Compliance Parts.
1-855- 565-8388
Reply
Old Jan 20, 2022 | 10:07 PM
  #3  
Justin Raney's Avatar
Justin Raney
Thread Starter
Melting Slicks
 
Joined: Apr 2021
Posts: 2,189
Likes: 82
Default

Yes I emailed and called him no response but that's everything including the brown wire mod. The orange wire 1st terminal and purple wire 3rd terminal in on lower connector. The top connector green wire 2nd terminal and brown wire 3rd terminal on the bottom replaces a different green wire and cut the brown loop wire according to the instructions.
Reply
Old Jan 20, 2022 | 11:00 PM
  #4  
Johnny Hardcore's Avatar
Johnny Hardcore
Melting Slicks
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
Default

Originally Posted by Justin Raney
Yes I emailed and called him no response but that's everything including the brown wire mod. The orange wire 1st terminal and purple wire 3rd terminal in on lower connector. The top connector green wire 2nd terminal and brown wire 3rd terminal on the bottom replaces a different green wire and cut the brown loop wire according to the instructions.
Sounds like you did it correctly. Very frustrating.
Did you compare your steps to YouTube videos to ensure you pulled and capped the correct green wires?

I found success on my first attempt.
Sorry I've got nothing other than punting to Rich.

Reply
Old Jan 20, 2022 | 11:09 PM
  #5  
Justin Raney's Avatar
Justin Raney
Thread Starter
Melting Slicks
 
Joined: Apr 2021
Posts: 2,189
Likes: 82
Default

Originally Posted by Johnny Hardcore
Sounds like you did it correctly. Very frustrating.
Did you compare your steps to YouTube videos to ensure you pulled and capped the correct green wires?

I found success on my first attempt.
Sorry I've got nothing other than punting to Rich.
Yes it worked when I first installed it and took the correct relay out but did have it happen again so I cut the brown loop wire. It started saying other stuff I'd never seen before "pull key wait 10 seconds" was what I would first get after installing I still get that code sometimes and " steering column locked". The steering columns been unlocked since I got the car last year and I installed the lcm5 after having the 2mph fuel cut issues. I did leave a voicemail at compliance parts and sent email. I looked earlier and looks like every wire is installed correctly. This will kill a starter after repeated attempts I have to let the car sit for 15-30 minutes before retrying.
Reply
Old Jan 21, 2022 | 07:29 AM
  #6  
Johnny Hardcore's Avatar
Johnny Hardcore
Melting Slicks
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
Default

You may still be getting the 2mph cutoff because your battery isn't going to full charge. How old is the battery (do you keep it on a trickle charge?) and have you checked to see how many volts it reads on a meter?

Also, do you know or have you checked to see if your car has the dealer installed "K-Harness" bypass device? Some have had to remove that bypass after installing the LMC5 and found success .

Link to the column lock sticky on the C5 forum:

https://www.corvetteforum.com/forums...ky-please.html

I'm thinking you have a battery going south or you have a K-Harness installed. It's Winter time, so definitely could be a battery issue. Just a guess/hunch.

Reply
Old Jan 21, 2022 | 11:08 PM
  #7  
Justin Raney's Avatar
Justin Raney
Thread Starter
Melting Slicks
 
Joined: Apr 2021
Posts: 2,189
Likes: 82
Default

I've got a new battery from walmart 5 months ago. It reads good voltage and my alternator puts out 13.4-13.7 on the gauge cluster. When i checked the fuses underhood with the power probe some read 14.2 volts and some read 13.7 volts.

Tho today after fumbling out the bcm yesterday to make sure i had correctly installed the lmc5 module brown wire and cut the loop as in the instructions i didn't run into any issues. Started the car 5-6 times to test drive with the new cam, balancer install as well as top off the transmission fluid i didnt have any problems with the pull key wait 10 seconds or steering column locked. Not sure why it does it sometimes.
Reply
Old Jan 21, 2022 | 11:08 PM
  #8  
Justin Raney's Avatar
Justin Raney
Thread Starter
Melting Slicks
 
Joined: Apr 2021
Posts: 2,189
Likes: 82
Default

Originally Posted by Johnny Hardcore
You may still be getting the 2mph cutoff because your battery isn't going to full charge. How old is the battery (do you keep it on a trickle charge?) and have you checked to see how many volts it reads on a meter?

Also, do you know or have you checked to see if your car has the dealer installed "K-Harness" bypass device? Some have had to remove that bypass after installing the LMC5 and found success .

Link to the column lock sticky on the C5 forum:

https://www.corvetteforum.com/forums...ky-please.html

I'm thinking you have a battery going south or you have a K-Harness installed. It's Winter time, so definitely could be a battery issue. Just a guess/hunch.
Whats a k harness and where would it be installed?
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-1

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
Old Jan 21, 2022 | 11:38 PM
  #9  
wrmiles's Avatar
wrmiles
Pro
15 Year Member
All Eyes On Me
Liked
 
Joined: Oct 2006
Posts: 515
Likes: 133
Default

Don't remeber the exact details, but I had trouble when I installed one of the LMC pigtails 180 deg out in the connector.
Reply
Old Jan 21, 2022 | 11:56 PM
  #10  
Johnny Hardcore's Avatar
Johnny Hardcore
Melting Slicks
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
Default

The K harness relay (if you have one) would be mounted on the brace under your dash to the left of the steering column with a zip tie. The wires from the K harness relay plugged into the wire harness under the column itself.






Reply
Old Jan 21, 2022 | 11:58 PM
  #11  
Justin Raney's Avatar
Justin Raney
Thread Starter
Melting Slicks
 
Joined: Apr 2021
Posts: 2,189
Likes: 82
Default

Originally Posted by wrmiles
Don't remember the exact details, but I had trouble when I installed one of the LMC pigtails 180 deg out in the connector.
I believe i put mine the same orientation as the ones i pulled out but its a possibility i'll have to check next time i have problems with it. One thing i notice is with the new cam installed if i don't let the gauges do a full sweep before starting it cranks a bit before starting vs letting it do a full sweep and starting right up.
Reply
Old Jan 22, 2022 | 08:04 AM
  #12  
Johnny Hardcore's Avatar
Johnny Hardcore
Melting Slicks
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
Default

Originally Posted by Justin Raney
I believe i put mine the same orientation as the ones i pulled out but its a possibility i'll have to check next time i have problems with it. One thing i notice is with the new cam installed if i don't let the gauges do a full sweep before starting it cranks a bit before starting vs letting it do a full sweep and starting right up.
That shouldn't be an issue. Was the car tuned properly post cam install?
Reply

Get notified of new replies

To lmc5 issues





All times are GMT -4. The time now is 12:29 PM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE