UPDATE: IMPORTANT - PLEASE DO NOT ATTEMPT THIS UNLESS YOU HAVE MODERATE MECHANICAL EXPERIENCE. IT CAN BE VERY DANGEROUS IF NOT DONE PROPERLY.

Hey guys,

I was kinda bored on Saturday and decided to "exercise" my ABS/TCS pump just to see what would happen. It went very well and I actuated the pump about 5 times. No problems and everything appeared to be working properly. The pump actuated very quickly and best of all, no codes.

I know that this has been already discussed but for anyone interested, this is what I did:

1) Lift rear of car by using a large floor jack placed in the middle rear suspension cradle. I used a 2x10 piece of wood placed between the jack point and the cradle to avoid any damage.
3) Place jack stands under each lower control arm and slightly lower the car to bring the driveline to a more normal alignment. In other words, the suspension should not be hanging.
2) Start car and shift to second gear. Slowly begin accelerating. The ABS/TCS should come on at about 35 KM/H (20 M/H). This causes the pump motor to actuate which gets the brake fluid circulating. Repeat a few times.
3) Lower the car. You're done!

Before anyone chimes in on how it's much better to just drive the car aggressively enough to activate the ABS/TCS system; not everyone is comfortable with driving aggressively on the street or even in an empty parking lot. Furthermore, there is always a possibility of flat spotting your tires if you hit the brakes at a fast enough speed in the dry to cause the ABS to come on.

Lets face facts. There are also alot of members that never take their cars out in the rain. So, the ABS/TCS system is never actually used.

This procedure at least will get the system working which probably will extend its life and avoid having to deal with a seized ABS pump motor. Whether it actually helps or not, the jury is still out on that but at least it can't hurt and will let you know if everything is working the way it should. I've now decided to do this at least once or twice a year.

PS: You may get a C1221, C1222 and C1248 code initially due to the fact that the system senses no movement from the front wheels. This is normal for obvious reasons. Just turn off the car and start it again, the TCS system should reset and allow you to complete the procedure.

 

And you actually heard the pump running???

 

I need to step away from the computer, and get out into the garage and do some exercising.

 

I think it's always a good idea to check rarely activated functions occassionally. But, just as you may not be comfortable attempting to activate it on the street, others may be equally uncomfortable with your method. I would suggest going to a reputable dealer and having the technician bleed the brake system using a Tech 2. This, IMO, is the best method as it not only exercises the ABS system, it also completely refreshes the fluid in the brake system, including purging all the old brake fluid from the ABS circuit.

Luckily, I have my own Tech 2 and can do this sitting in my own garage but I recommend a dealer visit once a year or so to bleed the system if you're not inclined or capable of doing the service yourself.

 

And have the dealer screw up you car and cost you $100's if not $1000's to fix. Only thing I ever use a dealer for is Warrantee work or recalls. Under those circumstances, at least the manufacturer is somewhat involved. I would say this is the worst advice.

 

Yes, you are correct!!!
This method is not for everyone. I should have stated that at the beginning. It is only meant for people that are mechanically inclined and work on their own cars. Please, please do not attempt this if you have never lifted your own car! It is dangerous if you do not know what you're doing!

Ah yes, the famous Tech 2. Believe me, if I had one I would've done it that way. Unfortunately, it's too expensive for me right now but I definitely plan on getting one eventually.

 

I tend to agree with you on this one. I have a severe mistrust of dealers and thus I do everything myself. Whatever I can't do, I learn how to and get the required tools to do it or find a proper shop that I can trust (not easy to do).

 

Even though I do most of my own work and have over the past 30+ years, I have used dealers when it was necessary such as under warranty and when I don't have the necessary equipment or expertise. If you know how to do everything on these cars, bravo to you but most here do not and an independent shop can screw something up just as easily and badly as a crappy dealer shop.

Obviously, the prerequisite to handing over one's car to a dealer would be verifying that dealership has a reputation for doing good work. There are those that exist and they have been documented here. I personally have first-hand experience with dealers that did excellent work and would even warrant installation of mods on Corvettes.

Using a Tech 2 to bleed the brakes is simple - I figured it out the first time without much drama and it would be virtually impossible to screw the process up, even if you don't follow the prompts on the screen. If the tech is a certified factory-trained tech, bleeding with a Tech 2 is child's play.

And, yes, there are a lot of less than scrupulous and skilled dealers out there but there are good ones too. The Mini dealership I took my dd to during and after the warranty period is absolutely stellar and gets an A+ in service and technical expertise.

To each, his own . . .

 

No, you can't actually hear the pump due to the engine. But you do hear and feel the abs system actuating for about 3 - 4 seconds and stopping the rear tires. This means the pump has to run for that to happen.

 

The Tech 2 cycle is done with the engine off and key in the "On" position so you can clearly hear the pump working. It actually is a fairly long process and it has you pump the brake pedal during the ABS unit activation cylce to ensure fluid is running through the ABS circuit. Also, It does go through quite a bit of fluid so you must frequently refill the reservoir. It leads you through the bleeding of each corner of the car so the entire system is flushed once you've completed the cycle.

 

I did a seminar at one of the Bloomington Gold events a few years back. During the seminar I asked a group of 30 or so C5 and C6 owners :

"How many of you have actually used or actuated ACTIVE HANDLING or ANTI LOCK Brakes?

Three people raised their hands.

Folks,,, Thats SAD!

I asked the question:
When you activate your ANTI LOCK BRAKES can you steer the car?

Only a couple people knew the answer!

The answer is YES!

You can hammer the brakes and as the antilock (and or AH if you have it) is active, you can steer around the object in front of you.

If you have never use your Antilock brakes or AH, you are seriously shorting yourself when it comes to an actual event when you need to use it to prevent an accident.

If you have not planted your foot to the floor from a 40 mph roll, your really missing out on a very important training exercise.

It really doesn’t hurt your car and you won’t leave four black marks on the road!

You might actually be AMAZED at how well your car stops.

I have a pretty fast car and I tell my friends it STOPS a LOT faster than it goes!

Hope this helps someone in the future!

Bill

 

The steps sound good in theory but per step 2 to keep the suspension from hanging, placing jack stands under the rear tire control arms does nothing to realign the rear tires when the car is lowered. Lowering the car with jack stands under the rear tire control arms - doesn't realign the rear suspension. The rear suspension hangs exactly the same as when the car is completely jacked up at the rear suspension cradle. In fact I can pull the jack out from under the car and the car rests entirely on the jack stands under the rear tire control arms compressing nothing. I can see why the rear suspension needs to be re-aligned because with the suspension (tires) hanging, the brake lines rub up against the rear wheel rims. Running the rear at 20 mph with the suspension hanging doesn't seem to be a very good idea. All I can see to do is obtain a second jack and once rear of the car is jacked up, use the second jack to compress the rear tire suspension and then place a jack stand under the rear tire control arms. I do have a Hotchkis sway bar installed at the rear suspension but the OEM Corvette had one too as I remember so I don't think the sway bar is keeping the rear suspension from being re-aligned. Where am I going wrong?

 

I just go to autocross. Much easier.

 

Find an open area, that is grass covered. Accelerate to 20 MPH and spike the brakes. Repeat this, 2-3 times....

 

Guess it is time to invest in a Tech2. Nothing like more toys governed by software which will undoubtedly save me time - not.

 

In south Florida, always rains somewhere, I exercise both brakes and traction once a month (at least),

 

Easy fix for my codes and I never would have thought of it on my own..I did 5 or 6 times of idling up to 25 to 30 until ABS started attempting to shut down my free spinning back tires. Rear lower A-frames are a bit challenging to jack up and still get it to sit on stands like it normally sits on the garage floor but for me it didn't really matter. Point of it all is my ABS hasn't been used in over 10 years but once on stands it only took 15 minutes or so to cycle ABS on and off and my codes are gone and no problems since.

 

I have had a Tech 2 clone for years and printed out he instructions to do it, however, being an avid autocrosser, they do regularly get exercised. Did it once when I first used the Tech 2 but since then have given the case and instructions to several club members and they have used it on their cars. Sometimes after changing brakes, clutch, etc you can get a soft pedal after bleeding, help two of my friends with that. The Tech 2 for under $300 is a useful tool.

 

Thank you for posting here on the forum about this issue. We fixed my 2002 259,200 mile C5Z ABS issue today—the 20 and 40 Amp Maxi Fuses in the engine compartment were switched, and when we “exercised” the ABS pump we blew the 20 Amp fuse (it should’ve been the 40 amp fuse—the car is new to me in the last 14 months).
After the first, brief exercising of the ABS pump is when we found out the two fuses were “location” swapped—as the fuse blew and we could no longer exercise the ABS pump.
We then put a new 20 Amp fuse and the 40 Amp fuse in the correct slots and continued to exercise the ABS pump.
We then test drove the C5Z and no ABS/Traction Control/Active Handling error came on.
We tested the four wheel speed sensors and they were fine.
We then flushed the brake fluid from the ABS pump individually at all four brake locations with new Prestone DOT 4 MAX brake fluid.
The tool we used to exercise the ABS pump and test the wheel speed sensors is the Kingbolen K7 Bi-directional scan tool.
I drove the car home without and issues and will autocross it on October 4, 2025, a good test to see if we fixed the issue.
Ken, of Toys 4 Life C5 Corvette YouTube channel documented and did the work on my Corvette—the video posted on September 21, 2025.

 

Michigan turn arounds - cold mornings - I drift the tail a bit exercise at least twice a week going to work!!