Skiddadale

Im looking for some help with my 2005 350z jap import AT.

I had a bad connection on the battery and lights flickered, then I got AT Check light solid.

Took it to gearbox specialist who have tested the signally and power is getting to TCM in valve body (they had the valve body sump off and everything is ok apart from the solenoids not getting power or signal to them it appears)

My 1st question is, I am confident this was caused directly by a power surge, therefore the valve body should be fine, can the TCM unit be replaced on its own? and if so is it coded to the car?
Also where could I get one from? is there an aftermarket one that would work?


My 2nd question is, has anyone on here took the TCM apart, is there any components on there that could be replaced by a bench technician say?

Thank you in advance

Conway_160

iTrader: (1)

Have you thought of just doing a mt swap? Might be cheaper and its alot stronger than the at.

FOOKhonda

iTrader: (1)

You could buy a used at tranny for at most 1,000$ or so with quite low miles. How would a mt swap be cheaper? And the mt is not that much stronger, and honestly this is the first thread I think I've even seen of an at tranny problem, you see a new thread of something wrong with an mt almost everyday...

Stronger - barely
More reliable - definitely not.

Conway_160

iTrader: (1)

The 6mt is WAY stronger, you will see the MT hold 700+hp and a built at will hold maybe hold 500hp Of the top 25 fastest VQ's 20 of them are 6 speeds...and there is one auto...Ill say that proves how much stronger they are..

You see problems with the CD01's syncros but rarely with the CD09.

Skiddadale

Its not a mechanical problem, perhaps even just the TCM module needs resetting.

What I have noticed is that if I put it into tiptronc mode and change it down from 3rd to 2nd, it does change the gearbox, so there is definatetly some communication and activity.

Ive read part of the AT Nissan service manual and it says that the TCM module is not OBDII, so you don't expect to get any diag from it.

It also says to reset it you Nissan would use a Consult II diag unit , put the car into R, press the accelerator fully down and clear the error (Im pretty sure the gearbox garage I took it to never did this) they did say it was the TCM module though as they could not get any diag from it (but they wouldn't by the looks)


below is the service manula page I was reading:-
DTC P1703 TRANSMISSION CONTROL MODULE (ROM) PFP:31036
Description ACS003NV
The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The
TCM controls the A/T.
On Board Diagnosis Logic ACS003NW

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “TCM·ROM” with CONSULT-II is detected when TCM memory ROM is malfunctioning.
Possible Cause ACS003NX
TCM.
DTC Confirmation Procedure ACS003NY
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch to “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for A/T with CONSULT-II.
3. Start engine.
4. Run engine for at least 2 consecutive seconds at idle speed.
5. If DTC is detected, go to AT-129, "Diagnostic Procedure" .
Diagnostic Procedure ACS008AZ
1. CHECK DTC
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULTII.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform “DTC confirmation procedure”. Refer to AT-129, "DTC
Confirmation Procedure" .
Is the “TCM·ROM” displayed again?
YES >> Replace control valve with TCM. Refer to AT-237, "Control
Valve with TCM and A/T Fluid Temperature Sensor
2" .
NO >> INSPECTION END