r34 gtr abs not working

[bigboss59400]

Hello, 

I have a full stock r34 gtr however the brakes locked.

Brakes are fine (pedal feels good), I had to go over 90km h under rain to make it locked.

no brake leakage and brake fluid level is ok.

I'm using used (good conditions) winter tyres.

abs goes on and off after ignition is switch on.

I had a fault code 72 that I clear and it didnt get back.This fault code was relating to TPS (MFD show correctly the TP) I also checked the TPS signal on the abs connector and voltage is within spec (0.5 - 4v)

I checked the wheel sensors from the connector of the abs module I got values (using a cheap chinese ohmeter) between -0.5k and +8k (depends at which speed I turn the wheel ) with average/rest at 1.2k 

during the wheel sensors signal measurements; I moved/shake the wheel sensors wires/connectors to make sure there is no short or open in the loom/connector/sensor.

I'm out of idea ? can it be a relay ? fuses ?

best regards

[bigboss59400]

anyone ?

[ggub]

Replacing the relay fixed my ABS when it stopped working.

[bigboss59400]

on a r34 gtr too ?

you are talking about the relay inside the abs pump I guess ?

do you recall the reference/model of the relay so that I could order upfront

[ggub]

R33 gtst - it's on the side of the ABS pump and has three plugs going into it.

I don't know what the part number for your car would be - I got mine from Kudos Motorsport.

[bigboss59400]

Thanks for your answer however now I'm out of idea...

 

I have performed the following tests :

- continuity test between the wiring of the abs pump and the abs ECU

- ring abs sensor are in good condition and have the correct number of teeth (46)

- all fuses are ok

- tyres are globally in same condition; is within +/- 10mm

 

- I have electrically disconnected the abs pump to test it :

* relay are ok (80 ohms and I can "hear" them when I powered them)

* solenoid valves seems ok (4 ohms or 8 ohms and consummes 1.5A or 3A; it will depends if it's an inlet or outlet)

* the abs motor is working

 

My questions :

- I have a front limited diff slip, is it possible that's making some trouble with the ABS ?

- should I open the abs pump to check the valves ?

- should I go for new tyres ?

- where can I found the software to use with nissan consult to connect to the abs ECU (so that I could log some infos)

 

Any other idea maybe ?

 

Thanks for your time

[bigboss59400]

Anybody succeed to read data from the ABS module without the nissan consult II ?

(because this tool is nearly impossible to get...)

Edited February 16, 2021 by bigboss59400

[GTSBoy]

Roll the car into a Nissan dealership?

[bigboss59400]

In France, no chance to find one with such device...

(I mean consult I)

[GTSBoy]

Really? France. The home of Renault. 50% of Nissan-Renault.

[bigboss59400]

Yes... because this cable and the card associated work only for R34 GTR that's why it make it so special !

some dealer even ask what is a nissan skyline r34 gtr haha

[bigboss59400]

so I have bleed the entire system and the wheels are still locking

I have dixcel m or z type brake pads (I dont know if that could be an issue somehow )

I have order a consult 1 we will see
if I am still getting into trouble I will change the master brake cylinder, abs pump and abs control unit ...

best regards

[bigboss59400]

I finally got a (german) consult

I was able to do the active test with success (meaning the abs pump should be ok)

the wheel data seems to be ok too, they are between +/-1kmh between each other and they are matching the real speed.

I was not able to do the self diagnostic with the consult; I might do something wrong in the process I guess (see picture)

 

Edited February 26, 2021 by bigboss59400

[bigboss59400]

I'm suspecting some solenoids being blocked as my wheels are still locking (my feeling is it seems to be the front only ) so I will dissasemble the pump
I have made a test this morning (7am at 1 degre; the road was dry but we some humidity on it; sorry I don't get the english word for it )

you can clearly see from the picture that my abs control seems to react correctly !
 

if the solenoids valve are in good cobdition, I will put everything back to stock :

• no winter tyres
• OEM pads
• new flexible hoses (avionic )
• new brake master

thanks

[bigboss59400]

So to conclude,

My assumption was false, based on the curves I provided we can see that the wheels has locked but the ABS release some pressure to unlock them...

Replacing the winter tyres by some regular tyres give a much better feeling too (but I don't think it was necessary)

So at the end, a bleed of the system + some cleaning on the calipers (with a lot of WD40) seems to have done the trick....yes it was such simple

French test has been passed with success this time

I can finally drive legally in a few weeks hopefully

THanks for having a look into my problem.

[GTSBoy]

Interesting. Probably worth your while to consider getting the calipers off, stripped down and checked out. Some new seals might be justified. See if the pistons are all moving freely, etc etc.