Power brake
Race Director
Joined: Apr 2017
Posts: 10,247
Likes: 888
From: Hickory NC
2025 C5 of the Year Finalist - Modified
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2020 C5 of the Year Finalist - Modified
St. Jude Donor '17 thru '26
This may be a better question in the C5 Tech section, but, a few things to check before posting in Tech to give the members as much diagnostic info as possible.
Have you pulled DIC codes? (If you have not tried pulling codes before, see this:
List any codes that are showing up. Be sure and identify whether they show H (history) or C (current).
How long have you had your car and did this just start happening or has it been doing it?
Any changes (modifications) to your car?
Do you notice any loss of power going uphill?
First guess is possibly the 02 sensors, but the experts in Tech will have better ideas.
Best wishes for an easy fix.
Have you pulled DIC codes? (If you have not tried pulling codes before, see this:
How long have you had your car and did this just start happening or has it been doing it?
Any changes (modifications) to your car?
Do you notice any loss of power going uphill?
First guess is possibly the 02 sensors, but the experts in Tech will have better ideas.
Best wishes for an easy fix.
Safety Car
Joined: Jul 2010
Posts: 3,965
Likes: 386
From: Chandler AZ
Thread Starter
Heel & Toe
Joined: Jul 2021
Posts: 15
Likes: 1
I just got the car last weekend 98 convertible. I will try to pull codes Sunday.
I took tc off and in perf mode can't enter compition mode as I have a error message to service traction control system and abs system. The previous owner said it needs wheel speed sensors ..
I took tc off and in perf mode can't enter compition mode as I have a error message to service traction control system and abs system. The previous owner said it needs wheel speed sensors ..
Administrator
Joined: Mar 2001
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From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
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Moved to C5 Tech.
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Safety Car
Joined: Jul 2010
Posts: 3,965
Likes: 386
From: Chandler AZ
Power brake booster.
At first I thought the same thing, but thought car ran rough/bad when you applied the brakes, then read it again.
If car is shut off, if you press brake pedal, is it easy to push like when car is running, or hard to push, you should have enough vacuum left in it for at least one power brake assist.
Then it will get harder to push as the vacuum is used up after a couple of pumps of brake pedal or so, let us know if that's what happens or if something different happens.
At first I thought the same thing, but thought car ran rough/bad when you applied the brakes, then read it again.
If car is shut off, if you press brake pedal, is it easy to push like when car is running, or hard to push, you should have enough vacuum left in it for at least one power brake assist.
Then it will get harder to push as the vacuum is used up after a couple of pumps of brake pedal or so, let us know if that's what happens or if something different happens.
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
This has absolutely nothing to do with your power brakes. If you want to power brake you will need a visit to a tuner. There are some parameters in the pcm that will need to be changed.