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New owner R32 Need help 4WD light ON

Greetings from USA.

I recently took ownership of this R32 GTR. I don't know much about this car since there are not many here. The 4wd light stays on but the ABS and Hicas goes off normally after engine start.

After some search here is what I have done:

Checked under hood and dash fuses all good

Checked the LED error and flashing code 21.

Checked the TPS(last owner installed a new unit)

Checked the TPS voltage using a scanner and shows .4v throttle closed.

Checked the fluid level in trunk. (right between min and max)

I printed out R32 manual and followed diag for code 21. Measured voltage at attesa ECU pin 47 and 48. Found .4V at connector. Flow charts says to replaced attesa ECU. Makes sense since the voltage signal is getting to the 4WD ECU but the ecu still flashes this problem then ECU defective.

I replaced the attesa ECU and still same code 21 and 4wd light on.

I ran 2 new wires from ECU to attesa ecu replacing the two tps signal wires. The 4WD light went out and torque gauge is working now.

I bleeded the system and everything seems to be good now until I found out the CEL is on now (apexi ECU lights up exhaust warning for CEL).

In the mean time since the 4wd is working some what now I started getting the relay clicking and hicas light problem so I replaced the accumator and that problem seems ok now.

I bleeded the system again and now a lot more fluid is flowing out so I think the accumator helped a lot with the pressures.

I have a apexi power fc and when the cel is on the exhaust overheat will stay on. The CEL is for water temp sensor, air temp sensor and tps.

I checked the wires again and found the black wire from the ecu needs to go to attesa, tps, ect, and air temp sensor.

So now I wires up sensors one by one while checking the 4wd light.

Everything still works fine with water temp and air temp sensor and attesa wired up, however once I wire up the tps ground wire, the 4wd light turns back on.

I rechecked the tps voltage again and it's looks good...so now stuck.,,

Also this condition is same with stock ECU and apexi ecu

Any ideas?? thanks.

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  • 8 years later...

I know this was so long ago but I currently have the same issue with mine and was told to change the ecu tps from 10% to 90% instead of 0% to 100%. Doing this seemed to work for others I'm going to try it on mine

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