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:

code P0856

Thread Tools
 
Search this Thread
 
Old Feb 8, 2023 | 11:07 AM
  #1  
teagarner's Avatar
teagarner
Thread Starter
2nd Gear
 
Joined: Feb 2023
Posts: 2
Likes: 0
Default code P0856

i have a question about my 2004 Corvette . i left the interior lights on and the battery went dead and when i charged the battery again the dash board said "service engine soon ". and the ABS light and the traction control lights where on and the error code that shows' up is P0856 traction control torque request circuit . i replaced the battery and it is still not fixed can anyone help me?
Reply
Old Feb 8, 2023 | 08:44 PM
  #2  
C5 Diag's Avatar
C5 Diag
Moderator, Tech Contributor
Supporting Lifetime Gold
10 Year Member
Veteran: Air Force
Liked
Community Favorite
 
Joined: Sep 2013
Posts: 15,605
Likes: 4,060
From: Cape Coral, Florida
Default

Welcome to the Forum !!...do you have a DVOM that can possibly read "duty cycle" or Hertz and are you OK with electrical testing ??...picture below of the Requested Torque Signal wire so since it has a 5 volt reference I would check it either at the PCM pin 13 on the C1 connector or at the EBCM pin 12...your wiring schematic is below....checking for the 5 volts is better with a headlight bulb just to be sure there is no high resistance on that wire...just checking for volktage won't cut it...if you have a better scan tool you can read the duty cycle data PID and it should read from 10-90%..if this seems like this is "all Greek to you" find yourself a diagnostic shop in your area…since the battery went dead I’d have it load tested at your favorite parts store before trying to diagnose this.

Reply
Old Feb 10, 2023 | 07:18 PM
  #3  
teagarner's Avatar
teagarner
Thread Starter
2nd Gear
 
Joined: Feb 2023
Posts: 2
Likes: 0
Default

Originally Posted by C5 Diag
Welcome to the Forum !!...do you have a DVOM that can possibly read "duty cycle" or Hertz and are you OK with electrical testing ??...picture below of the Requested Torque Signal wire so since it has a 5 volt reference I would check it either at the PCM pin 13 on the C1 connector or at the EBCM pin 12...your wiring schematic is below....checking for the 5 volts is better with a headlight bulb just to be sure there is no high resistance on that wire...just checking for volktage won't cut it...if you have a better scan tool you can read the duty cycle data PID and it should read from 10-90%..if this seems like this is "all Greek to you" find yourself a diagnostic shop in your area…since the battery went dead I’d have it load tested at your favorite parts store before trying to diagnose this.

itook it to a shop and they said it is an abs control modual that is discontinued and they would have to send it out for someone to rebuild it and put it back in for 1800$ is that sound right to you
Reply
Old Feb 10, 2023 | 07:50 PM
  #4  
mmartinez's Avatar
mmartinez
Melting Slicks
15 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Liked
 
Joined: Sep 2008
Posts: 3,138
Likes: 802
From: Espanola New Mexico
Default

Find another shop or two and get another estimate.
Reply
Old Feb 10, 2023 | 08:12 PM
  #5  
sleepingcougar's Avatar
sleepingcougar
Instructor
Liked
Loved
Community Favorite
 
Joined: Mar 2021
Posts: 134
Likes: 39
Default

clear the code and drive it for couple of days. the codes may disappear.
Reply
Old Feb 10, 2023 | 08:20 PM
  #6  
Smoken1's Avatar
Smoken1
.
Supporting Lifetime Gold
10 Year Member
St. Jude 10 Year Donor
Liked
Community Favorite
 
Joined: Apr 2013
Posts: 5,034
Likes: 1,156
From: Oregon
St. Jude Donor '14-'15-'16-'17-'18-'19-'20-'21-'22-'23
Default

There are 2 plugs and 6 torx screws that hold it in. Find another shop
Reply

Get notified of new replies

To code P0856





All times are GMT -4. The time now is 02:54 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
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-9
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