R33 GTR V-SPEC ATTESA Code 31 ET-S Solenoid or Circuit

[Dee JL]

Hello,

I have a R33 GTR V-Spec with a problem that originally started out as the 4WD and A-LSD light coming on after about 20 minutes of driving (hit or miss). I could turn the car off and turn it back on and it would go away for another 20 minutes. Now the lights are constantly on. I've checked the blinking red light on the ATTESA ECU and it is code "31 - ET-S Solenoid or Circuit". I've searched everywhere for a replacement solenoid and it doesn't seem to be a thing. And I have yet to see any wires that come from it. I've taken the pump relay and shorted the red and yellow wire together to see if the pump is still working, in which is does. Does anyone have any idea what could be the problem? Maybe a faulty ground wire? Where would I look for the wires that belong to the ET-S Solenoid?

[JBeach]

On 12/29/2020 at 6:31 PM, Dee JL said:

Hello,

I have a R33 GTR V-Spec with a problem that originally started out as the 4WD and A-LSD light coming on after about 20 minutes of driving (hit or miss). I could turn the car off and turn it back on and it would go away for another 20 minutes. Now the lights are constantly on. I've checked the blinking red light on the ATTESA ECU and it is code "31 - ET-S Solenoid or Circuit". I've searched everywhere for a replacement solenoid and it doesn't seem to be a thing. And I have yet to see any wires that come from it. I've taken the pump relay and shorted the red and yellow wire together to see if the pump is still working, in which is does. Does anyone have any idea what could be the problem? Maybe a faulty ground wire? Where would I look for the wires that belong to the ET-S Solenoid?

Did you ever figure your issue out? I’m also having an issue where the front will not disengage with car off and I have a fault code 31 as well. Any help will be much appreciated!

[joshuaho96]

On 11/19/2021 at 11:35 PM, JBeach said:

Did you ever figure your issue out? I’m also having an issue where the front will not disengage with car off and I have a fault code 31 as well. Any help will be much appreciated!

It's a very simple circuit, chase the wires. Shouldn't be seeing any battery power to the solenoid with the car off, the positive side is shut off by the ignition switch.

[JBeach]

On 11/21/2021 at 11:42 AM, joshuaho96 said:

It's a very simple circuit, chase the wires. Shouldn't be seeing any battery power to the solenoid with the car off, the positive side is shut off by the ignition switch.

Yeah I’ve been using the diagram attached. After about 12-24hrs with car off, my front wheels finally spin freely. But again, when cars running pressure is built and doesn’t seem to disengage.
The code 31 was from a friends ET-S computer I installed on mine. When the code is present I can not turn at all because my front is locked. My original computer doesn’t give any fault codes and doesn’t lock the front up when driving. I gave up and took it to a mechanic and he thinks it’s the ET-S solenoid. Unfortunately, the complete pump isn’t cheap for a “I think it’s the solenoid”. 

[joshuaho96]

On 11/22/2021 at 4:27 AM, JBeach said:

Yeah I’ve been using the diagram attached. After about 12-24hrs with car off, my front wheels finally spin freely. But again, when cars running pressure is built and doesn’t seem to disengage.
The code 31 was from a friends ET-S computer I installed on mine. When the code is present I can not turn at all because my front is locked. My original computer doesn’t give any fault codes and doesn’t lock the front up when driving. I gave up and took it to a mechanic and he thinks it’s the ET-S solenoid. Unfortunately, the complete pump isn’t cheap for a “I think it’s the solenoid”. 

Instead of just guessing you should unplug the solenoid connector and measure the voltages on all the pins with the ignition on. If you see the ATTESA controller engaging the pump solenoid and the pump is locking up the transfer case then there's no point in trying to replace the pump assembly, it's just doing what it's being told to do. I would be concerned that you have something in your car's harness that is injecting voltage to the pump solenoid even though the ATTESA controller is not commanding it. That would definitely throw a fault code as the controller can detect what appears to be either a short circuit or open circuit.