[Z06] ABS Defeat
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,549
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From: Roanoke Virginia
ABS Defeat
I would like to D/C the ABS. Pulling the fuse #37 apparently interferes with steering. There is another relay which also controls the wipers. How exactly is this defeated? Can I put a switch in line with the wires to the ABS itself, or is it set up to defeat other components if this is detected?
Tech Contributor
Joined: Oct 1999
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From: Charlotte, NC (formerly Endicott, NY)
Any particular reason why you want to do this? Fuse 52 cuts some of the power to the EBCM and Fuse 5 cuts the rest of the power although there are some other things attached to Fuse 5 that I haven't chased down. Fuse 37 isn't involved. You can also put a switch in line with the fuse and be able to switch ABS on and off. Since 52 is a 40 amp fuse I would probably lean toward putting the switch in line with Fuse 5 which is only a 10 amp fuse.
Bill
Bill
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,549
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From: Roanoke Virginia
Car does not stop. Maybe it was AH, I don't care to find out again. To pull ABS fuse and differentially diagnose. If improved, leave off until new brakes prove ABS is beneficial. Been through this before.
Sorry, it was fuse no. 27, in engine compartment. C6. That influences power steering (undocumented). Also no. 3 relay, but that is also windshield wipers. Solution, Will put a switch in further downstream. I was wondering if anyone else ever did this.
Alternative is to reprogram car body computer ABS, but I have not seen that.
Sorry, it was fuse no. 27, in engine compartment. C6. That influences power steering (undocumented). Also no. 3 relay, but that is also windshield wipers. Solution, Will put a switch in further downstream. I was wondering if anyone else ever did this.
Alternative is to reprogram car body computer ABS, but I have not seen that.
Tech Contributor
Joined: Oct 1999
Posts: 41,036
Likes: 9,798
From: Charlotte, NC (formerly Endicott, NY)
That is a very rare problem. GM had the problem on their trucks built from 99 through 2004 and that were driven in the North. It was due to corroded wheel speed sensors which caused spurious wheel speed signals. The solution on those vehicles and on my Tahoe with Active Handling which would turn on when accelerating from a stop was to clean the sensors and re-install them. Since those sensors are different than the Corvette sensors I doubt the same solution would work but it might be worth while checking the wiring and wiring connections to the sensors.
If your ABS is activating the brake pedal will be vibrating and if you are on dry pavement and slamming the brakes on the car will shudder like mad. It feels like total chaos but that is how you know for sure if the ABS is activating. If you don't get that then it isn't activated.
Other than that all I can tell you is that you will be missing a valuable tool if you run without ABS. I find I can slow much faster using ABS than I can without it.
I suspect your problem lies some other place than with the ABS or AH systems.
Bill
If your ABS is activating the brake pedal will be vibrating and if you are on dry pavement and slamming the brakes on the car will shudder like mad. It feels like total chaos but that is how you know for sure if the ABS is activating. If you don't get that then it isn't activated.
Other than that all I can tell you is that you will be missing a valuable tool if you run without ABS. I find I can slow much faster using ABS than I can without it.
I suspect your problem lies some other place than with the ABS or AH systems.
Bill
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,549
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From: Roanoke Virginia
I hit the pedal hard. There's some delay in how long it took to give out from under my foot / resistance - I'll fix that too. Then what? Smoooothly - nothing. No pulsations, etc. I'll go try slamming on the brakes a few times tomorrow just to test it out. I'll turn off the AH and see if it makes a difference. I'll pull fuse #3 (minifuse) and see if the power steering and abs changes. This is a ridiculous problem. I think I'll do it right now.
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,549
Likes: 1
From: Roanoke Virginia
ok test run. Why does the steering stiffen up when pulling the abs fuse anyway? something is retarded.
Result: I wasn't braking hard enough. I am used to the Brembros on the Nissan. The corvette's are are not brick wall brakes. Alot of pedal effort is required here, and there is definately better stopping without ABS, but tires lock up and the steering's a pain. This system needs some work.
Project: Toss the brakes and get some real ones, SS lines, and stickier tires. Then the ABS will do what it should. The brakes will feel like brakes. And I won't get hounded with notices and heavy steering.
Result: I wasn't braking hard enough. I am used to the Brembros on the Nissan. The corvette's are are not brick wall brakes. Alot of pedal effort is required here, and there is definately better stopping without ABS, but tires lock up and the steering's a pain. This system needs some work.
Project: Toss the brakes and get some real ones, SS lines, and stickier tires. Then the ABS will do what it should. The brakes will feel like brakes. And I won't get hounded with notices and heavy steering.
Tech Contributor
Joined: Oct 1999
Posts: 41,036
Likes: 9,798
From: Charlotte, NC (formerly Endicott, NY)
ok test run. Why does the steering stiffen up when pulling the abs fuse anyway? something is retarded.
The Variable Effort Steering (VES) system, or MAGNASTEER II® varies the amount of effort required to steer the vehicle as vehicle speed changes or lateral acceleration occurs. At low speeds, the system provides minimal steering effort for easy turning and parking maneuvers. At high speeds, the system provides firmer steering (road feel) and directional stability. When the system senses lateral acceleration, steering becomes firmer to reduce oversteering. The Electronic Brake Control Module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator. The actuator adjusts the amount of power steering assist to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the Antilock Brake System (ABS) wheel speed sensor inputs to determine vehicle speed. When the EBCM senses vehicle speed, it commands a current to the actuator that is most appropriate for each speed. The system also uses inputs such as Handwheel position, wheelbase, understeer coefficient and steering ratio to calculate lateral acceleration. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds, no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuitry to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only.
So when you pull the fuse you disable the EBCM and put the Magnasteer in max effort mode like when you are driving at high speed.
The Variable Effort Steering (VES) system, or MAGNASTEER II® varies the amount of effort required to steer the vehicle as vehicle speed changes or lateral acceleration occurs. At low speeds, the system provides minimal steering effort for easy turning and parking maneuvers. At high speeds, the system provides firmer steering (road feel) and directional stability. When the system senses lateral acceleration, steering becomes firmer to reduce oversteering. The Electronic Brake Control Module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator. The actuator adjusts the amount of power steering assist to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the Antilock Brake System (ABS) wheel speed sensor inputs to determine vehicle speed. When the EBCM senses vehicle speed, it commands a current to the actuator that is most appropriate for each speed. The system also uses inputs such as Handwheel position, wheelbase, understeer coefficient and steering ratio to calculate lateral acceleration. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds, no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuitry to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only.
So when you pull the fuse you disable the EBCM and put the Magnasteer in max effort mode like when you are driving at high speed.
Tech Contributor
Joined: Oct 1999
Posts: 41,036
Likes: 9,798
From: Charlotte, NC (formerly Endicott, NY)
Result: I wasn't braking hard enough. I am used to the Brembros on the Nissan. The corvette's are are not brick wall brakes. Alot of pedal effort is required here, and there is definately better stopping without ABS, but tires lock up and the steering's a pain. This system needs some work.
With the stock Z brakes you shouldn't have any problems stopping better than any production Nissan made and it shouldn't take much effort to get into ABS. I slam mine from 60+ mph all the time when approaching a certain hair pin turn at the Go Kart Track we autocross at and non-Corvette people are amazed at how quickly the car slows.
Bill
With the stock Z brakes you shouldn't have any problems stopping better than any production Nissan made and it shouldn't take much effort to get into ABS. I slam mine from 60+ mph all the time when approaching a certain hair pin turn at the Go Kart Track we autocross at and non-Corvette people are amazed at how quickly the car slows.
Bill
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Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,549
Likes: 1
From: Roanoke Virginia
Thank you for your excellent response which I will make into reference material. This should be in the Faq.
Brake considerations: I'll give SS lines a try before delving into a big brake set like the Nissan (read "big $$$".) Perhaps the ss lines will harden up the Z06 brakes and make less effort despite it's much lighter weight (rotors are the same size). The brake set mentioned was not the Brembros on the late model 350Z, oh no, but rather the aftermarket big brake set for the 1990 300ZX. I miss that reality-defying decelleration and brick-wall rock hard pedal action. I want that in the Z06 also.
Brake considerations: I'll give SS lines a try before delving into a big brake set like the Nissan (read "big $$$".) Perhaps the ss lines will harden up the Z06 brakes and make less effort despite it's much lighter weight (rotors are the same size). The brake set mentioned was not the Brembros on the late model 350Z, oh no, but rather the aftermarket big brake set for the 1990 300ZX. I miss that reality-defying decelleration and brick-wall rock hard pedal action. I want that in the Z06 also.