Speedo to auto. transmission problem

[Geo.jnr]

Hi, all you out there.
I have a 1993 3.0TD which is ace, apart from an annoying electrical problem.
The speedo is eratic. It can jump up to 35mph when turning the ignition on (at standstill). It can register zero when traveling. It can fluctuate between zero and whatever speed I am traveling at.
This affects the automatic transmission, which in turn affects fuel economy.
The worse occasion was when traveling down a dual carriage-way, the speedo only registered 30mph. This then didn't allow the auto. transmission to shift up and I was revving at 3500rpm, moving slowly and burning fuel like there was no tomorrow! This problem is also intermittent.
I have consulted a local auto. electrician who said he needed wiring diagramms, some of which I have found on the net, but none show the link between the speed sensor (instrument cluster) and the auto. box.
Any help would be greatly appreciated.

[stara]

the speed sensor is part of the ECU as is the transmission control, so either the speed sensor is effed or the ECU is confused. The sensor wire is marked GL, this could be green/lilac. Allegedly you can reset the ECU by disconnecting BOTH batteries for 10mins, i would suspect a sensor or wiring fault though. I believe the speed sensor is on the middle side of the gearbox (there is also a speed sensor on the diesel pump) but my knowledge of speed sensor locations is poor.

[Silversurfer]

Speedo to Auto Transmission Problem

Hi Geo.Jnr

If you give me your Email address I will send you the wiring diagrams for the Surf and the ECU diagnostic codes and how to extract them. I tried to post them to the Forum but they exceed the Forum size limit.
Toyota say the ECU rarely fails so, as you say, it may be a sensor or most likely loose/dirty connections, particularly earth connections.
There is a colour code at the top of the main wiring diagram which indicates that WL is Green/Blue.
If the 'Engine Check'light on the tacho lights up when driving or doesn't go out when the engine starts it usually indicates a fault with the ECU/Sensors which can be checked using the diagnostic codes.
Is the Tacho also erratic ? as this is driven by a pick-up sensor
From the wiring diagram the speed sensor you mention on the instrument cluster WD1 is shown as linked with the pre-heat timer
Hope this helps - would be interested to know how you get on just it case it happens to others.

Regards

Silversurfer

[Richardireland]

Hi Silversurfer

I have an auto transmission problem and I note from your post that you have the wiring diagram and the diagnostic procedures and codes. I have a 94 3.00 Surf auto. Would it be possible for you to email these to me?

Regards

Richard

[Artful_dodger]

Hi Silversurfer

I have an auto transmission problem and I note from your post that you have the wiring diagram and the diagnostic procedures and codes. I have a 94 3.00 Surf auto. Would it be possible for you to email these to me?

Regards

Richard

Richard,,,got to your own thread, i have posted a reply to it

Cheers
Paul

[riff raff]

Hi Geo.Jnr

If you give me your Email address I will send you the wiring diagrams for the Surf and the ECU diagnostic codes and how to extract them. I tried to post them to the Forum but they exceed the Forum size limit.
Toyota say the ECU rarely fails so, as you say, it may be a sensor or most likely loose/dirty connections, particularly earth connections.
There is a colour code at the top of the main wiring diagram which indicates that WL is Green/Blue.
If the 'Engine Check'light on the tacho lights up when driving or doesn't go out when the engine starts it usually indicates a fault with the ECU/Sensors which can be checked using the diagnostic codes.
Is the Tacho also erratic ? as this is driven by a pick-up sensor
From the wiring diagram the speed sensor you mention on the instrument cluster WD1 is shown as linked with the pre-heat timer
Hope this helps - would be interested to know how you get on just it case it happens to others.

Regards

Silversurfer

hi silver i would like that info if you wouldnt mind emailing it to me at dallasanderson1@yahoo.com.au

[adpsimpson]

Wow, digging up a 2 year old thread to reply to a 5 year old post to ask for an email from someone who's not been on the site since 2007

All the documents are available for download on Matt's site here: http://daemon4x4.org/portal/index.php Click on "downloads index," then they're arranged in sections including toyota electrical, mechanical etc. I've got a 3.0 so haven't gone looking for the 2.4 diagrams, but they should be there.

[riff raff]

thanks

Great mate thanks for that

Wow, digging up a 2 year old thread to reply to a 5 year old post to ask for an email from someone who's not been on the site since 2007

All the documents are available for download on Matt's site here: http://daemon4x4.org/portal/index.php Click on "downloads index," then they're arranged in sections including toyota electrical, mechanical etc. I've got a 3.0 so haven't gone looking for the 2.4 diagrams, but they should be there.