Nistune Forums

Hey guys i just tuned a series II R33 with a auto Z32 ecu ( 41P14 ) it tuned up sweet and drives sweet but it wont kick down properly. It will kick dwn from 3rd to second but if your travelling @ say 10kph it wont kick down to 1ST. Generally when this happens you can be assured its a manual base ecu not an auto ecu.

Any suggestions?

The data in Nistune led me to believe it was a manual trans ecu which explains the lazy kick down but a quick search on the net reveal the 41p14 ecu to actually be auto. Any one confirm this?

i have also tried using another auto ENT file and it makes not difference.

im wondering if 300zx's had some code to stop them kicking back to first? as there seems to be no difference in pin locations between r22 and z32 for the auto control (pins 5, 14, 15, 56 and 57).

cheers
capt confused.

Hello ..

What is the setup of the car?

Could you post your .bin?

Thanks,
Andrew

I have no experience with a Z32 automatic ECU on an automatic R33, but most likely the problem is caused by the fact that the Z32 ECU and R33 ATCU are incompatible.

Do you get a code 54 from the ECU ?
because then it's a clear case of incompatibility and you will need to find another way to have the gearbox controlled.
(eg. an aftermarket/standalone ATCU)

it may be also something simple as re-adjusting the TPS, but keep in mind the Z32 uses a different TPS sensor for automatics...it has an extra WOT switch built in that is used by the (Z32) ATCU as the kickdown signal.
For the Z32 this switch is connected directly to the Z32 ATCU (pin 21).

I don't know if the R33 ATCU has a similar setup, but it could be the TPS on the R33 doesn't have this WOT switch and the ATCU relies on a kickdown signal from the ECU (which the Z32 ECU lacks as far as I know)..

-Eric

It hasn't been a tried and tested combination before. I transplanted the R33 maps into the Z32 auto image several weeks ago and updated the RB25DET thread accordingly, but no feedback yet

Weren't too sure if there were going to be compatibility issues or not. So far I have heard no problems with using R32 ECU with R33 maps on them, but not a Z32 ECU

I assume the signals from the engine ECU get fed to the AT ECU via the comms link (if this link was down then AT DTC code would appear in consult) but as Eric mentioned, with the TPS idle switch missing on the RB25DET engine it could cause issues with the Z32 in regards to the trans perhaps?

Eric wrote:I have no experience with a Z32 automatic ECU on an automatic R33, but most likely the problem is caused by the fact that the Z32 ECU and R33 ATCU are incompatible.

Do you get a code 54 from the ECU ?
because then it's a clear case of incompatibility and you will need to find another way to have the gearbox controlled.
(eg. an aftermarket/standalone ATCU)

it may be also something simple as re-adjusting the TPS, but keep in mind the Z32 uses a different TPS sensor for automatics...it has an extra WOT switch built in that is used by the (Z32) ATCU as the kickdown signal.
For the Z32 this switch is connected directly to the Z32 ATCU (pin 21).

I don't know if the R33 ATCU has a similar setup, but it could be the TPS on the R33 doesn't have this WOT switch and the ATCU relies on a kickdown signal from the ECU (which the Z32 ECU lacks as far as I know)..

-Eric

Sorry Torques i wont post the bin as its not tune or bin related and there is a lot of work in the map that a customer has paid good money for..


Eric your spot on, i read today that the z32 tps (same as GTR) has a kick down switch and this is what the Z32 ecu is looking for. The car runs perfect other than it has no aggressive kick down, std kick down is working ie on highway it will drop out off lookup and into second but generally wont drop instantly at WOT.

I just need to find the WOT tps pin on the z32 ECU... anyone know off the top of their head?

I will transplant a z32 tps and post the results.

the WOT switch on the Z32 is not connected to the engine ECU...only to the ATCU

Trent - what were the results for this? Will shoot you an email regarding this