1jz into MX83 Cressida A340 Issue

**brady89** · 04-01-2010, 01:30 PM

Hi All'

I have just purchased a MX83 Cressida with a 1jz conversion out of a jzx81 and am having an issue with the Auto transmission only selecting 1st and Reverse.

When the conversion was first done it had a manual box in it and was running fine on the auto ecu, once the previous owner blew the box he changed it back to auto (auto was taken out of another cressida that previous owner had driven and he said it was driving fine) and since it has changed back to auto it will only select 1st and Reverse.

I am sure it will be something electrical but after looking around on the forums I just cant pin point what exactly is the issue. I have not tried another ecu as yet. Thinking maybe the Auto ecu was modified to run the Manual box and now that its back to running and auto again that could be the issue.

I am planning to take it to an auto electrician in the next few days to look into it.

Any advice or ideas as what it could be would be appreciated!!!!

Cheers

**seamonsta** · 04-01-2010, 08:20 PM

Good buy man, if you are out Penrith way you could talk to Sasha at Canak Autosports, he wired my cressida and works on quite a few so he knows his shit.
Tim

**CrUZida** · 05-01-2010, 11:45 AM

Chances are its a wiring problem.
And trying to diagnose someone elses wiring is a nightmare.

Generally though, with miswired auto's L = 1st, 2 = Drive, D = Overdrive (ie, manual shifting is required)

If you put it in D, and it definitely takes off in 1st, but won't shift into 2nd, then there is a good chance that the speed sensors are not wired in.

There is one speed sensor that goes from the dash to the ecu (SPD) and one that goes from the gbox to the ecu (SP2) (this one is NOT the speedo drive, but another one).
I vaguely recall that some of the older auto's have the SP2 signal going through the ABS ecu, and then to the engine ecu, but can't remember if the JZX81 is one of them.

The one from the dash is the best one to hook up.

**brady89** · 05-01-2010, 12:39 PM

Thank you very much for all that information!!! Going to have another look tonight'

I unplugged a plug last night and now I have 1st,3rd,overdrive, reverse, neutral..

Hopefully can sort it out tonight'

If anyone has any more info/suggestions just let me know!!

Cheers!

**brady89** · 05-01-2010, 09:39 PM

car now has 1st (when selecting 1st) then when selecting 2nd will hold 2nd gear for about 2seconds then automatically goes into 3rd then when selecting drive car goes into overdrive and reverse and neutral work ok..

im having to manual shift all gears.. getting closer to resolving the issue i think... so atm automatically holding 2nd for a second then going into 3rd and having to manually change gears.

**Gem** · 05-01-2010, 10:59 PM

Check Tps voltages as tps input determines gear shifting. in position 2 it shouldn't goes to 3rd, its a wiring problem. dont forget speed sensor no.2, hopefully its working otherwise u shouldnt have any upshifting

**brady89** · 07-01-2010, 07:59 AM

Thanks for the Reply Gem.. Do you know what the TPS voltages should be reading ??

**Gem** · 13-01-2010, 07:50 PM

VTA - E2 should be 0-1V at idle and 4.4v - 5v at WOT. VTA voltages should gradually increase as you open throttle. at wot it should be 4.4v - 5v.

**Demon** · 16-01-2010, 06:41 PM

This is strange that there is no shift in the box. Would say the other gents are rite that there would be a wiring isue. Gearbox dose not just go, toyota made them well, What 1jz is it ? On the 1jz-gte vvti the SPD runs from your multiplex to the ECU and splits and runs to speedo, power steering and cruise controll. There are two senors on the box which will be as a pick up to the ECU and there is a large plug at the rear which relays info to ECU. Make sure you getting contannuaty on all these points. On the 1jz iv had it that the gear selector on the box was not giving me contact for the neutral start, i then opened the unit cleaned the points and re greased and it worked well. Make sure you are getting these points conected and make sure you are getting your points from the shifter conected. There are two switches on there, one for drive and drive 3, the other one is for park but i would not bother with that so much thou. Have a look where your ECT switch has landed up but its straight forward, On your pinouts for ECU you will have a pin for ECT which just needs IG+ thru a switch and that will kick in your solinoids in the box. I landed up with pinouts for a manul box so that was not there, had to do sum tracing to find it. OD2 will be your light for the cluster which will flash when IG+ is on and when it starts it should go off. Check where your STP has landed up. It should run from your brake switch to the ECU and to the unlock solinoid on the shifter, try and get this conected because the box has got like a back draft when you brake ( it helps to slow down and not so hard on brakes)