C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Code 24 - Hypertech Related?

Thread Tools
 
Search this Thread
 
Old Jun 19, 2011 | 08:11 PM
  #1  
azrocketman's Avatar
azrocketman
Thread Starter
Racer
 
Joined: Aug 2009
Posts: 289
Likes: 1
From: Tucson Arizona
Default Code 24 - Hypertech Related?

I've been chasing a somewhat intermittent Code 24, Vehicle Speed Sensor, problem on my 1986 convertible (aluminum heads, automatic) since I purchased the car in July 2009 with 73,000 miles. I swapped the ECM today thinking that this may be a contributor to the problem (after previously reseating the instrument cluster connectors and replacing the VSS on the transmission). Still no joy.

During the swap I was surprised to find a Hypertech chip assembly in the place of the stock MEM CAL. The Hypertech part number is 156342.

My questions are: Is it possible that there is some change in the Hypertech programming that can cause the ECM to throw a Code 24? What benefit does this Hypertech chip set provide?

Does anyone have a stock MEM CAL available for my car? The car is a stock L98 (to the best of my knowledge), automatic, and aluminum heads. The replaced ECM has a paper tag with the following information:

Service Number: 1227165
AANM
862251
M621796970

Thanks,

Steve
Reply
Old Jun 20, 2011 | 05:36 PM
  #2  
C409's Avatar
C409
Le Mans Master
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2005
Posts: 6,475
Likes: 565
From: Clearwater Florida
Default

I seriously doubt that your issues are related to the hypertech prom ... on L98's the hypertech uses the ARAP bin's spark maps because they're a bit more aggressive and usually changes the on / off settings for the engine cooling fan ... not much more than that ........... I would check the wiring between the VSS and the ECM ... it helps if you have the factory Helms service manual ... there are diagnostic flow charts and wiring schematics that will make the job easier .........
Reply




All times are GMT -4. The time now is 05:10 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