ASR issue solved - ZR-1 Net Registry Forums

secondchance · 01-23-2017

Since my first engine pull/rebuild in spring 2014 my ASR has been throwing code H65 – adjuster assembly fault. Although “ASR” lit up on display screen was annoying, this did not hamper drivability of the car. I tried disconnect/reconnect of power, checked the fuse and even checked wiring from the ABS/ASR control module behind the driver side seat to the fuse behind the battery and found anything obvious. This lead me to suspect the ASR unit itself.
Naturally this part is no longer available and checking Ebay found multiple ASR assembly off of LT1 and LT4 cars but none from a LT5 car. Assembly, except for the mounting hardware and orientation, looked very similar so I took the plunge and picked one up for about $90. This part sat in my closet for about a year.
Last week I noticed my throttle pedal had a resistance half way through its travel – sort of felt similar to old Holley 4 barrel carb with mechanical secondaries. Last Saturday, after wrapping up Roadster’s Z, I had Jim take a look inside the air horn as I depressed the throttle. Surprise! Only the primary butterfly was opening. Further noticed 1st pulley (from the bottom) became stationary (coinciding with throttle pedal resistance) as 2nd pulley continued to rotate as throttle pedal was depressed.
Now that I only could run the car at about ¼ throttle max, I had to resolve this issue. So, last Sunday I took used ASR I bought, finally removed the assembly itself out of the bracket and cover and confirmed it to be an identical part to what was on the car. Replacing this part was pretty straight forward. Once new part was installed, throttle pedal movement became normal. When I started the car and goosed the throttle ASR warning light stayed off! No more service ASR light!
Now that the problem was solved, I got curious with how this assemble functioned.
Below are a few pics of different stages of disassembly. Unless you are a master watchmaker, this part is not serviceable.

Basically, first and second pulleys (from the bottom) act as one single unit due to internal connection by a wound up spring and its tension resulting in throttle pedal movement to throttle body. When rear wheel slippage is detected, electric motor operated by signal from ECBM (?) turns the half circle gear which determines maximum throttle opening and throttle pedal travel beyond max throttle dictated by the electric motor action is absorbed by slipping of 1st and the 2nd pulley. This slipping is handled by wound up spring found between the two pulleys. Plastic pulley on top has nothing to do with interface between these two pulleys and there to connect cruise control servo to throttle pulley.

Bottom line, if you have later car with ASR and ASR assembly breaks, have no fear. LT1/LT4 assembly will work fine and these parts are plentiful!

Dynomite · 01-23-2017

Anti Slip Regulation (ASR)......found on 92'-95'.

Excellent photo coverage

Summary......you are saying....
LT1 and LT4s have identical ASR?
I will check my 95' in a few minutes to locate the module and button

The ASR Control Module is located on Drivers Side of Engine.......guess that is what you took apart

The Black Cover right next to the Drivers Side Front Wheel.......

secondchance · 01-23-2017

Quote:

Originally Posted by Dynomite

Anti Slip Regulation (ASR)......found on 92'-95'.

Excellent photo coverage

Summary......you are saying....
LT1 and LT4s have identical ASR?
Where is the module you took apart located on the ZR-1?
Where is the button located for ASR (On and Off)?
I will check my 95' in a few minutes to locate the module and button

LT1 and LT4 cars have identical ASR motor assembly (driver side of the engine).

Component I took apart is under the hood on the driver side. Black plastic cover identifies "ASR".

ASR switch is located right above headlight switch. It has a graphic of tail of corvette fish tailing. Default is on. Pushing the switch defeats ASR.

Roadster · 01-23-2017

Yun, nice write up with great pics and explanation....glad you got that corrected. To have full throttle again......

secondchance · 01-23-2017

Quote:

Originally Posted by Roadster

Yun, nice write up with great pics and explanation....glad you got that corrected. To have full throttle again......

I could have figured out how to rig and bypass the whole thing. Real treat is to get it working the way it came and get rid of "Service ASR" light without resorting to pulling he bulb.

rkreigh · 01-24-2017

I'd really like to bypass mine and sell the parts to someone who needs them.

Seems like the right cables will be all I need to do that.

Let's talk!

The ASR stands for "A simply ridiculous" device for me on the LSV and the car even has a special box from the old Ramp chevy guys that's bypasses the ASR on strartup (rare).

For me the ASR is just added weight, and the cables are sticking and hanging up the throttle in the cold. Seems to come and go.

Parts left out don't break and the C4 ASR was good in it's day, not so much with 500 at the tire as it's so far outside the original design, it's more dangerous than good.

mike100 · 01-24-2017

I used to appreciate in on my old '95 LT1 car, but I daily drove that rain and all. It's ok to have when it rains.

Kevin · 01-24-2017

I drove an lt1 car with asr and it was a weird experience the first time it came in. I don't like it and if i had a later car I'd probably find a way to get rid of it

secondchance · 01-24-2017

Quote:

Originally Posted by rkreigh

I'd really like to bypass mine and sell the parts to someone who needs them.

Seems like the right cables will be all I need to do that.

Let's talk!

My guess is, if you get a throttle and cruise cable from 90-91 car along with 2 throttle cable clips, you should be able to replicate early car without ASR.
My ASR was non functioning when I modified the motor so I have no idea how it will behave with 500+ hp. I guess I can always just turn it off.

secondchance · 01-24-2017

Actually, I can reassemble my broken one with ASR motor drive disengaged and pull the bulb behind the warning display panel. However, EBCM has to stay since EBCM controls ABS also.

Pulley to the throttle pedal and pulley to the throttle body can be permanently fixed so it behaves as one pulley.

01-23-2017	#1
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,721	ASR issue solved Since my first engine pull/rebuild in spring 2014 my ASR has been throwing code H65 – adjuster assembly fault. Although “ASR” lit up on display screen was annoying, this did not hamper drivability of the car. I tried disconnect/reconnect of power, checked the fuse and even checked wiring from the ABS/ASR control module behind the driver side seat to the fuse behind the battery and found anything obvious. This lead me to suspect the ASR unit itself. Naturally this part is no longer available and checking Ebay found multiple ASR assembly off of LT1 and LT4 cars but none from a LT5 car. Assembly, except for the mounting hardware and orientation, looked very similar so I took the plunge and picked one up for about $90. This part sat in my closet for about a year. Last week I noticed my throttle pedal had a resistance half way through its travel – sort of felt similar to old Holley 4 barrel carb with mechanical secondaries. Last Saturday, after wrapping up Roadster’s Z, I had Jim take a look inside the air horn as I depressed the throttle. Surprise! Only the primary butterfly was opening. Further noticed 1st pulley (from the bottom) became stationary (coinciding with throttle pedal resistance) as 2nd pulley continued to rotate as throttle pedal was depressed. Now that I only could run the car at about ¼ throttle max, I had to resolve this issue. So, last Sunday I took used ASR I bought, finally removed the assembly itself out of the bracket and cover and confirmed it to be an identical part to what was on the car. Replacing this part was pretty straight forward. Once new part was installed, throttle pedal movement became normal. When I started the car and goosed the throttle ASR warning light stayed off! No more service ASR light! Now that the problem was solved, I got curious with how this assemble functioned. Below are a few pics of different stages of disassembly. Unless you are a master watchmaker, this part is not serviceable. Basically, first and second pulleys (from the bottom) act as one single unit due to internal connection by a wound up spring and its tension resulting in throttle pedal movement to throttle body. When rear wheel slippage is detected, electric motor operated by signal from ECBM (?) turns the half circle gear which determines maximum throttle opening and throttle pedal travel beyond max throttle dictated by the electric motor action is absorbed by slipping of 1st and the 2nd pulley. This slipping is handled by wound up spring found between the two pulleys. Plastic pulley on top has nothing to do with interface between these two pulleys and there to connect cruise control servo to throttle pulley. Bottom line, if you have later car with ASR and ASR assembly breaks, have no fear. LT1/LT4 assembly will work fine and these parts are plentiful!

01-23-2017	#2
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,797	Re: ASR issue solved Anti Slip Regulation (ASR)......found on 92'-95'. Excellent photo coverage Summary......you are saying.... LT1 and LT4s have identical ASR? I will check my 95' in a few minutes to locate the module and button The ASR Control Module is located on Drivers Side of Engine.......guess that is what you took apart The Black Cover right next to the Drivers Side Front Wheel....... __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 01-23-2017 at 01:16 PM.

01-23-2017	#4
Roadster Join Date: Mar 2014 Location: Warrington PA Posts: 1,914	Re: ASR issue solved Yun, nice write up with great pics and explanation....glad you got that corrected. To have full throttle again...... __________________ Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1974 L-82 355 Vert. 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member

01-24-2017	#6
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,087	Re: ASR issue solved I'd really like to bypass mine and sell the parts to someone who needs them. Seems like the right cables will be all I need to do that. Let's talk! The ASR stands for "A simply ridiculous" device for me on the LSV and the car even has a special box from the old Ramp chevy guys that's bypasses the ASR on strartup (rare). For me the ASR is just added weight, and the cables are sticking and hanging up the throttle in the cold. Seems to come and go. Parts left out don't break and the C4 ASR was good in it's day, not so much with 500 at the tire as it's so far outside the original design, it's more dangerous than good. __________________ 95 390 LPE ZR1 (505 rwhp) LSV = Lingenfelter Super Vette Twin Turbo 2003 Z06 (800 RWHP)

01-24-2017	#7
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: ASR issue solved I used to appreciate in on my old '95 LT1 car, but I daily drove that rain and all. It's ok to have when it rains.

01-24-2017	#8
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: ASR issue solved I drove an lt1 car with asr and it was a weird experience the first time it came in. I don't like it and if i had a later car I'd probably find a way to get rid of it __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

01-24-2017	#10
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,721	Re: ASR issue solved Actually, I can reassemble my broken one with ASR motor drive disengaged and pull the bulb behind the warning display panel. However, EBCM has to stay since EBCM controls ABS also. Pulley to the throttle pedal and pulley to the throttle body can be permanently fixed so it behaves as one pulley.