Help, R33 Gtr V-Spec Locked In 4Wd

[Shuyin]

So I recently installed an Power FC into my 1996 R33 GTR V-Spec, works like a dream. I was driving it home from the tuners and started to get a little load in the wet, it was normal so I kept on going. The next day when I went to reverse the car there was a ton load in the transfer case and the front Torque gauge was sitting on 30!

So put the car up on stands and sure enough the car was locked in 4wd. When I disconnected the pump at the connector and bled the actuator at the back of the transfer, it allowed the front wheels to turn on their own, so transfer case and hydraulics work. The cylinder also moved fine.

So summary is that the ATTESA system will pressurise, causing the transfer case to engage, but will not depressurise, causing it to stay locked in 4wd. There was no warning light on the dash. Bleeding the system causes the transfer case to disengage.

I have done some searching and ruled out the following:

The tires and wheels are the same diameter with similar wear.

The system is pressurising so the pump is fine.

I checked the plugs that connect the pump to the loom and they were fine, no corrosion.

Transfer case is working, so haven't cooked the clutch pack.

Any solutions or if anyone else has had this problem please let me know.

Thanks

Shaun

[GTSBoy]

Check the tyre pressures first.

[Shuyin]

I will check tonight. I'm thinking that it might be an issue with the TPS?

[tricstar]

yeah if TPS wires have been change with Power FC install?? then the Attessa could be getting the opposite signal ie. full throttle when there is no throttle and vise versa, have had this and they are the symptoms...ask installer if this is the case

[Shuyin]

Builder confirmed that no wires were taken out of the TPS

[Moodles2]

Might be a problem with the G-sensors (under the centre console), usually they only play up if you've physically messed with them.

[JBeach]

On 12/11/2012 at 10:25 AM, Shuyin said:

So I recently installed an Power FC into my 1996 R33 GTR V-Spec, works like a dream. I was driving it home from the tuners and started to get a little load in the wet, it was normal so I kept on going. The next day when I went to reverse the car there was a ton load in the transfer case and the front Torque gauge was sitting on 30!

So put the car up on stands and sure enough the car was locked in 4wd. When I disconnected the pump at the connector and bled the actuator at the back of the transfer, it allowed the front wheels to turn on their own, so transfer case and hydraulics work. The cylinder also moved fine.

So summary is that the ATTESA system will pressurise, causing the transfer case to engage, but will not depressurise, causing it to stay locked in 4wd. There was no warning light on the dash. Bleeding the system causes the transfer case to disengage.

I have done some searching and ruled out the following:

The tires and wheels are the same diameter with similar wear.

The system is pressurising so the pump is fine.

I checked the plugs that connect the pump to the loom and they were fine, no corrosion.

Transfer case is working, so haven't cooked the clutch pack.

Any solutions or if anyone else has had this problem please let me know.

Thanks

Shaun

Did you ever figure out what the issue of was?! I’m currently having like symptoms where I’m locked as soon as I start the engine. 24hrs later the front wheels are free until I start the engine again (pump primes). I bought the car with power FC but now running Haltech 2500 elite with plug and play. Just looking to see what you were able to find out before I pull my hair out.