Error code 42
 

Hi my engine warning light came on. I ran the diagnostic and got error code 42

The car occaisionally stalls when, I go down a gentle slope, go down the gears, go into neutal and am just applying the brake. - only when going down slope

I had a mechanic look at it who suggested idle valve problem. He suggested temporarily taping off one of the small black frexible hoses which was not connected to anything (? idle valve)

Would this be the no. 1 speed sensor ?

Thanks in advance
P.

Find another mechanic. There a big difference between the IAC (Idle air controller) and the VSS (Vehicle speed sensor)

CODE 42 - Vehicle Speed Sensor - No "SPD" signal to ECU for 8 seconds when engine speed is between 2,500 RPM and 4,500 rpm (7M-GE) or 4,000 rpm (7M-GTE) and coolant temp is below 80 deg. C (176 deg. F) and neutral start switch is off. Trouble areas - Vehicle Speed Sensor Circuit, Vehicle Speed Sensor, ECU.

The speed sensor is located in the instrument cluster, and a part of the speedometer. You may need to find a new one.

code 42
 

Thanks for the reply,

I'll have a look at the instrument panel, but would a faulty instrument panel be related to the engine stalling when coming to a gradual stop ?

(In Ireland most of the toyota garages will not touch an import)

Well, the ECU is using it for something, hence the code. Also, with the age, you may need to get the IAC cleaned out. They do tend to gunk up over time and affect the idle process. The fact that it hasn't tripped a code yet simply means the IAC is still responding to the ECU, but the air passages for the IAC may be plugged with carbon gunk.

Maybe someone else on this forum knows how the ECU uses the VSS. Many cars today use them as part of the transmission control, as well as a minor part of the fuel mix algorithm. You may simply have a bad connection behind the instrument panel. Does the speedometer work OK? Mine has an intermittent buzzing coupled with a bouncy needle. I've noticed my cruise control will act funny when this happens, but most of the time, it is steady and smooth.

BTW, did Toyota never sell Supras in Ireland? What? A Toyota mechanic will not touch a Supra? Please elaborate. Sounds strange to me. The 7M-GE engine was also used in Cressidas. Did they not sell those either?

code 42
 

Yea, because a lot of Japanese imports are shipped to the country, they drive down the price of the non-imports, the main toyota dealers d'ont like that at all. So if you c'ant get your reairs done it could put you off buying one of the imports.
You could have import and non import versions of some cars, but I think most of the supras are imports from Japan, although some may have come in from UK dealers where the Toyota garages would do services on them. I d'ont know about the Cressidas. It was great about 10 yrs ago when all these exotic Jap cars started being imported (Had an FTO import, and a CRX import before the supra)

I had a look at taking off the IAV, its on top of the engine near the Toyota badge, but the lower screw is inaccesable - not sure whats involved in getting to that screw

As far as I know the speedo is OK - I will keep a close eye on it

code 42
 

Hi! --According to my HAYNES -Toyota Celica Supra 1979 thru 1992 all models workshop manual Number 92025 , code 42 is the VEHICLE speed sensor signal.
What that means ---????????? can anyone help further?