Brake Issues with 1999 Z71 Pickup

[Matt Porter]

Tony,

If I remember right, those were refered to as CIS? Continuous injection system? I had a couple of Audis with that system on them. And you're right, the only problem I had was the relays would fail. I use to rob them out of other 'unneeded' operations, as long as they match the 'normally open/normally closed' criteria. I didn't relize there were aftermarket relays that were cheaper so I would go without an accessory. The old VW bugs had that system on them right before they quit US sales. Now things are much more complicated with map sensors, mass air flow, O2 sensors, knock sensors....blah blah blah. You can't just use a screw driver and a 9/16" wrench to tune in your ride nowadays. Oh well, someday our grandkids will hook their ipods to our cars to tune them. Theres an idea that might be worth a million bucks. The 'phone/mp3/pda/car tuner' gizmo from Ronco, only three easy payments of 19.95, but wait, theres more. If you act now, we'll throw in a ...

Matt Porter

[Tony Turner]

Matt the CSI is a different system. CSI is a mechanical fuel injection system and it was used on VW Rabbits, Audi, BMW and a bunch of other cars in the mid '70's and early 80's.

The CSI system had fuel pump issues and cold start issues but for a mechanical system it worked pretty well.

The Jetronic system uses a Mass Air Sensor, oxygen sensor, temperature sensor, throttle position sensor and an ECU. The system is simple in design and flawless once they corrected the issue of turning the fuel pumps on inside the ECU and the high current draw burning the ECU board.

[Tony Turner]

O.K! I've learned a lot about the ABS system on a Z71 today. I just "thought" I knew enough about the system to repair it, well that's just not the case.

The reason I'm not seeing a code set in the computer is because my reader must not be able to read codes for the chassis so I need to either get one that will or take it to the dealer to have the codes read (I really don't want to do that).

While the system seemed to check out fine in my inspection and road test I was missing a symptom because I was ignoring it thinking it was normal (cause I'm a dumb axx).

Anyway, I noticed a very tiny growl when MB pulled away from a parking space with her foot on the brake and only moving 3 or 4 mph. I thought to myself "self! that was a weired little noise" and then just dismissed it. That noise was the anti-lock motor doing it's thing thinking one of the wheels is going slower than the others, or at least that's the thinking.

The truck gets a really good "going over" this weekend and I'll let you guys know what I find.

Later,
Tony T

[minniemobuddha]

did she have a tire replaced?it could be one size off(e.g. 205 as compared to a 215)and that would give thing fits.your code reader should have picked up on that.could be an actual computer problem.good luck.i think yer gonna need it.

[minniemobuddha]

didja ever get your brakes figured out???or was all that shrapnel on a certain highway in ne iowa from a certain truck that was blown up?

[Tony Turner]

I think we have it fixed but not sure.

A couple of weeks ago I pulled the front wheels and pressure washed everything really well and so far the lights have not come back on.

We'll see if it stays that way

Later,
Tony T

[KRS]

I have a 2001 Yukon XL that does the same thing.
If the lights come on I drive through a car wash that has 'bottom blast' spray.
That seems to clean it out for a while.
Last time I had it in the dealer, they cleaned the ABS speed sensor, per recall, so GM knows there is an issue.