Diagnostic Code 42

[meawls Lurker Find all posts View Profile Close meawls]

Hello there,

ECM warning light has been on for a while now. Took car to Toyota dealer who performed diagnostics and advised that the fault related to code 42 "Variable Speed Sensor".

The dealer could not tell me if it is something dangerous .. or even if it could be fixed.

On line searches have revealed exactly the same result ... what it is, but not if it can be fixed, how, and whether it is OK to keep using the car with that particular warning in place.

I have a big road trip planned in a few days, and don't want to be causing damage to the car or myself .... can anybody please help with this query ... over and above the fact that it's there and what it is!!


Cheers,

...Wisey...

[hawks667 Member Find all posts View Profile Close hawks667]

My list of codes shows 42 is vehicle speed sensor....

[hawks667 Member Find all posts View Profile Close hawks667]

[Guest Close Guest]

Some clues
http://www.yotatech.com/f116/code-42-43-a-225055/
http://www.supraforums.com.au/forum/...fixed-forever/

[meawls Lurker Find all posts View Profile Close meawls]

G'day Andrew,

Thanks very much mate ... that's about the closest thing I've had to a sensible answer!!

The clues suggest that something involving the speedometer cable behind the dash could be the culprit. Since the speedo/odo are still functioning perfectly this seems to be the cue to simply ignore the warning ... unless a particularly rainy day comes up and one feels like .. I dunno ... ripping the dash apart - or something silly like that!!!

Cheers, and thanks again!!

Wisey

[macaroon1 Advanced Member Find all posts View Profile Close macaroon1]

Mate. It should be a dead easy fix. My speed sensor lead bust a few years ago. Went to Toyota and just screwed a new complete sensor in...still got the old one, very possibly still works as I think it was just the lead that was broken!

120 series Part number...TO 8954360050
I paid the Toyota tax, best you go to a breakers. My speedo worked perfectly too, there was just a warning light on the dash (forgot which one). Went to a 4wd park with it flashing, went OK. I'd still be getting it fixed though for a long trip, its dead easy to do.
Thanks c.

[meawls Lurker Find all posts View Profile Close meawls]

Thanks Macaroon,

Ours is a 90 series, but I'll check out that part number.

As a bit of a "stop press" ... during a trip to Brissie on Thursday the engine light started flashing. As it flashed the sub tank "in use" light flashed. The other new symptom is that the right indicator flashed at double time when activated. Left side was unaffected.

Took me a while to work it out, but the ECM light flash sequence is 4 then 2. In other words it flashed 4 times, paused, then flashed a further two times - suggesting to me that it is now visibly demonstrating the "42" code. But what's with the subtank light flashing in cohort with it - not the 4/2, just a constant flash. Made no difference whether I had the sub or the main tank activated - it still flashed.

The flashing wasn't constant, and stopped from time to time. When it stopped, the subtank flash stopped too, but the indicator issue remained .

Otherwise the car's behaviour was completely unaffected. A bit unnerving until I worked out the flash sequence.

Hopefully this reflects purely the problem with the speed sensor and not a deepening issue which may affect the chip ... or whatever.
In any case I'll take Macaroon's advice and try to change out the lead and see if it all goes away!!

[scottkz Senior Member Find all posts View Profile Close scottkz]

The sub tank is also controlled by the engine ecu...for what reason i dont know... according to one of my wiring diagrams it says fuel temp??
The autos have 2 speed sensors
The rear one goes to the speedo then to the ecu
The front one is a back up they say but i think it gets used more
Your rear one will be working but could be a break between speedo and ecu
Or the front one may be broken or a break in wiring, simple test light to confirm the connection from plug to ecu is what id do first

[meawls Lurker Find all posts View Profile Close meawls]

.... The autos have 2 speed sensors...

Thanks Scott,

Ours is a manual - so does this mean it only has the one sensor??

Cheers,

[scottkz Senior Member Find all posts View Profile Close scottkz]

As far as i know yes just the one sensor.... your speedo works? Cruise control works?

[meawls Lurker Find all posts View Profile Close meawls]

Yep, everything normal apart from what I've described. Do you know where this sensor is physically located/what it looks like?? I'll have a go at checking it and its termination points to see if anything looks amiss.

Many thanks for your help with this.

[brissy Member Find all posts View Profile Close brissy]

speed sensor is on the right side of the output flange - rear end of your transfer case

[scottkz Senior Member Find all posts View Profile Close scottkz]

As said above its a 3 pin plug very last one on the transfercase. ...
Pins are power / signal / earth... pull your ecu out and get the part number off it....
Your engine ecu...? Has that been changed? History... how long have yiu had the car? Im just wondering if it has a auto ecu in it....

[meawls Lurker Find all posts View Profile Close meawls]

Thanks again Brissy and Scott. I'll take a good look in the morning - now I know where the darned thing is!!

History - I bought the car new in December 1996. Manual. ECU has never played up and therefore has never been changed - or even touched as far as I know.

You can probably guess what I'm going to say next .... where the hell is the ECU - and what does it look like??!! I will need to know this before I can pull it out and get the part number!

Hopefully there will be something visibly wrong with the speed sensor unit which will explain all of this (that is - the mythical "easy fix" we all dream about!!).

Sincerely appreciate your ongoing input!

[scottkz Senior Member Find all posts View Profile Close scottkz]

Its behind the glove box.... open box 2 little tabs each side release them then the whole box swings right down then inside the glovr box the black plastic unscrews ... youl then see the ecu
The ecu itself may be having a cry lol