ASR problems

[red 92]

Car sat all winter. Changed brake hoses to braided, bled brakes and started car in spring ASR now growls and pushes back on accelerator. turn ASR off and all is fine. brakes also feel good, would appreciate any help. Car is 92 LT1.:eyerole:eyerole

 

[ecss]

Car sat all winter. Changed brake hoses to braided, bled brakes and started car in spring ASR now growls and pushes back on accelerator. turn ASR off and all is fine. brakes also feel good, would appreciate any help. Car is 92 LT1.:eyerole:eyerole

If you're not getting an indication there is any thing wrong with the ASR system try bleeding the modulator valve bleed screw **** item #1 in the picture.****

The valve bleeding screw is located in the rear storage bin behind the drivers seat. If you try that make sure you protect everything from getting any brake fluid on it.

 

[red 92]

ecss Tks for the time and info. Iwill give it a try. red 92

 

[red 92]

Asr

ecss Bled the mod valve and bled all brakes again, may have helped slightly. Now when I start the car and without ever moving the ASR growls for maybe 30 secs then stops but when I touch the accelerator even slightly still in park it starts growling and the ASR ACTIVE light comes on. Would appreciate any other thoughts you might have. tks red 92

 

[Hib Halverson]

Is the ASR Service light on or has it been on?

Is the growl noise coming from under the hood or from behind your seat?

Do you have a 1992 Service Manual?

 

[ecss]

ecss Bled the mod valve and bled all brakes again, may have helped slightly. Now when I start the car and without ever moving the ASR growls for maybe 30 secs then stops but when I touch the accelerator even slightly still in park it starts growling and the ASR ACTIVE light comes on. Would appreciate any other thoughts you might have. tks red 92

That's strange because the pump if that's what's growling shouldn't be activated until the EBTCM does a self test at around 4 mph.

Was the ABS/ASR functional before you replaced the brake hoses?
Was any thing else done to the car?

When you turn the ignition on, does the Service ASR indicator go on and off after 2 seconds?
On the diagnostic connector above the drivers right knee use a piece of wire or paper clip and short
pin A to pin G.

Turn the ignition On. Look at the speedometer LCD and see if any codes are displayed for Module 9.

 

[red 92]

Asr

Is the ASR Service light on or has it been on?

Is the growl noise coming from under the hood or from behind your seat?

Do you have a 1992 Service Manual?

Hib The ASR service light has never been on except when first turning the key on, the growl noise is behind the seat, I do not have a Service Manual but looks like I need to get one. Tks red 92

 

[red 92]

Asr

That's strange because the pump if that's what's growling shouldn't be activated until the EBTCM does a self test at around 4 mph.

Was the ABS/ASR functional before you replaced the brake hoses?
Was any thing else done to the car?

When you turn the ignition on, does the Service ASR indicator go on and off after 2 seconds?
On the diagnostic connector above the drivers right knee use a piece of wire or paper clip and short
pin A to pin G.

Turn the ignition On. Look at the speedometer LCD and see if any codes are displayed for Module 9.

ecss ABS/ASR was functional. I have had the car 5 yrs no problems. Changed shocks and plug wires (taylor pro series). Beside that and the brake hoses nothing else done this winter. ASR light does come on when first turning key on. Don't know if this helps but held RPM at about 2000 for about 20 secs while pump growling and it stopped and ASR active light when out but when returned to idle, started growling again. Checked codes nothing there. tks for helping, red 92

 

[ecss]

Now when I start the car and without ever moving the ASR growls for maybe 30 secs then stops but when I touch the accelerator even slightly still in park it starts growling and the ASR ACTIVE light comes on.

Don't know why a ASR event would take place with no signals from the wheel speed sensors since the car
is not moving.

The EBTCM does monitor the wheel speed sensors, Throttle Position sensor and the engine rpm to determine
when an ASR event takes place. It can control the gas pedal, retard ignition timing or apply the brakes to the rear wheels.

Manual mentions the brake fluid used for a ASR event comes from the master cylinder prime pipe which is a hose on the driver side of the master cylinder and goes to the modulator valve which you bled.

Only thing mentioned about bleeding the brakes is you first bleed the prime pipe at the modulator valve first.
Then right rear, left rear, right front left front calipers.
Only use Dot 3 brake fluid.

The Tech 1 is the only tool mentioned to trouble shoot the system. Since no DTC's are setting the EBCM doesn't know anything is wrong. :eyerole

No trouble shooting flow charts fits your symptoms. :ugh

Is it possible rodents got into the car over the winter?
Where in PA are you located?

 

[red 92]

Don't know why a ASR event would take place with no signals from the wheel speed sensors since the car
is not moving.

The EBTCM does monitor the wheel speed sensors, Throttle Position sensor and the engine rpm to determine
when an ASR event takes place. It can control the gas pedal, retard ignition timing or apply the brakes to the rear wheels.

Manual mentions the brake fluid used for a ASR event comes from the master cylinder prime pipe which is a hose on the driver side of the master cylinder and goes to the modulator valve which you bled.

Only thing mentioned about bleeding the brakes is you first bleed the prime pipe at the modulator valve first.
Then right rear, left rear, right front left front calipers.
Only use Dot 3 brake fluid.

The Tech 1 is the only tool mentioned to trouble shoot the system. Since no DTC's are setting the EBTCM doesn't know anything is wrong. :eyerole

No trouble shooting flow charts fits your symptoms. :ugh

Is it possible rodents got into the car over the winter?
Where in PA are you located?[/Q

I have not noticed any evidence of rodents. Car was in a inhouse heated garage all winter. Looking like a not easy solution. Am located 20 mi north west of Pittsburgh. Appreciate your help tks red 92

 

[ecss]

This may be your problem.
It has been mentioned strange ASR problems have been caused by a corroded Red wire that is hot at all times
and supplies 12 volts to the EBTCM module.

I'm looking at a 93 service manual. If you look at your fuse block #1 under the hood there should be a 20 amp ABS/ASR ECU fuse. A red wire from this fuse goes into the same convoluted tubing the two wires from the DC motor that pulls on the cruise control and throttle body cable. The tubing runs along the driver side rocker panel and comes out in front of the driver side rear wheel. It then goes up and enters into the ABS/ASR compartment.
People have said if you peel back the convoluted tubing it will be full of road debris and the Red wire will be corroded and rotted to the point where it's almost broken or even shorted to other wires.

Here's a picture of the wiring harness with the convoluted tubing pulled off.

https://imageshack.com/i/eyvavAOlj




The picture below shows where the harness enters the vehicle. The problem in the harness is some where from that point to around the rocker panel area.

 

[red 92]

Asr

ecss Iwill check that wire. Over the weekend I put about 100 mi on the car. Idid the hard stop test, ABS active light came on both with the ASR turned on and off. The ASR does self test going up the driveway. I did another code check after the 100 mi. Got a 28 with A and B wired together and a H28 with A and G. If the small numbers 1,4,9 are module numbers H28 was on 4. Maybe this will help and I will check that red wire, sounds like a possibility. tks red 92

 

[Hib Halverson]

With pin G grounded, If you saw H28 in module 4, that's an ECM history code. At some time in the past you had a fault with quad driver module #3. QDM3 controls the A/C clutch and the cooling fans. I wouldn't worry about it. Now if the check engine light comes on our you see C28 when you ground A and G, then you need the Service Manual for it's diagnostic instructions.

When the ASR Active light is on, you hear growling behind you and feel pushback from the accelerator pedal, for some reason, the ASR controller is commanding a significant ASR action.

Not only is the ASR controller wanting to reduce the throttle opening, but it's also commanding rear brake intervention. Which generally only happens with vehicle speed below 30-mph and a lot of wheelspin present.

 

[red 92]

Asr

With pin G grounded, If you saw H28 in module 4, that's an ECM history code. At some time in the past you had a fault with quad driver module #3. QDM3 controls the A/C clutch and the cooling fans. I wouldn't worry about it. Now if the check engine light comes on our you see C28 when you ground A and G, then you need the Service Manual for it's diagnostic instructions.

When the ASR Active light is on, you hear growling behind you and feel pushback from the accelerator pedal, for some reason, the ASR controller is commanding a significant ASR action.

Not only is the ASR controller wanting to reduce the throttle oprninh, but it's also commanding rear brake intervention. Which generally only happens with vehicle speed below 30-mph and a lot of wheelspin present.

Hib Thank for the info . I have a set of manuals coming from EBAY. I have no check engine light now but will have them in case. red 92

 

[ecss]

ecss Iwill check that wire. Over the weekend I put about 100 mi on the car. Idid the hard stop test, ABS active light came on both with the ASR turned on and off. The ASR does self test going up the driveway. I did another code check after the 100 mi. Got a 28 with A and B wired together and a H28 with A and G. If the small numbers 1,4,9 are module numbers H28 was on 4. Maybe this will help and I will check that red wire, sounds like a possibility. tks red 92

Schematic shows two sources of power for the EBTCM. The ABS/ASR 20 amp fuse which is hot all the time.
Why does the module need a hot source all time
The other fuse is ENG2 and is hot when the ignition switch is in run, start or bulb test.

When you get time, pull the ABS/ASR 20 amp fuse and see if that disables the ASR only and if the ABS
still works. :L

If you have a manual fan switch to turn the fans on that will cause a ECM DTC 28.
That code does not turn on the service engine soon indicator.

 

[red 92]

Schematic shows two sources of power for the EBTCM. The ABS/ASR 20 amp fuse which is hot all the time.
Why does the module need a hot source all time
The other fuse is ENG2 and is hot when the ignition switch is in run, start or bulb test.

When you get time, pull the ABS/ASR 20 amp fuse and see if that disables the ASR only and if the ABS
still works. :L

If you have a manual fan switch to turn the fans on that will cause a ECM DTC 28.
That code does not turn on the service engine soon indicator.

Tks I will try the fuse and check the red wire. I do have a lower temp fan switch in the driver side head. Comes on at 205 and off at 180 keeps pretty steady at 196 but never gets back down to 180 unless going down a long hill so I spliced in a manual switch to turn fan off when I hit open road. been working out good for 3yrs. Guess I'm old school and don't like the high temps.

 

[red 92]

Tks I will try the fuse and check the red wire. I do have a lower temp fan switch in the driver side head. Comes on at 205 and off at 180 keeps pretty steady at 196 but never gets back down to 180 unless going down a long hill so I spliced in a manual switch to turn fan off when I hit open road. been working out good for 3yrs. Guess I'm old school and don't like the high temps.

ecss I checked the red wire, some road crap in the tubing but the wires were o k . Guess I will use the off switch and keep driving. tks for your interest and your help.

 

[ecss]

ecss I checked the red wire, some road crap in the tubing but the wires were o k . Guess I will use the off switch and keep driving. tks for your interest and your help.

Did you pull the under the hood ABS/ASR 20 amp fuse and see what the symptoms were?

 

[red 92]

Did you pull the under the hood ABS/ASR 20 amp fuse and see what the symptoms were?

ecss I could not find that fuse

 

[ecss]

You won't find that fuse because it doesn't exist.

It looks like on a 92 a fusible link was used.
Disconnect the negative battery cable.
Remove driver side side gill panel.

Look behind and below the battery and you will see the battery jumper block. One of the cables
is from the positive terminal of the battery and supplies 12 volts to a bunch of fusible links.

Remove the stud nut securing the fusible links and clean the fusible link terminal lugs
then reassemble. Might want to coat the terminal lugs with die electric grease.

Water from the cowl dumps on to this area and can cause corrosion on the fusible link terminal
lugs.

Here's a video showing the fusible links.

▶ 1992 Corvette fuse locations - YouTube