Code 51

[toml]

Is code 51 only applicable at idle?

At idle or with the engine off, the car reports no codes.
If I give the engine a quick rev, it reports a code 51 then goes back to normal.

I assume this is because the ECU detects a difference in the TPS output so reports code 51... but I just wanted to check that it was normal behaviour.


Thanks,
Tom

 

[toml]

For reference:

Code 51: Switch Signal

Diagnosis

* No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.

Trouble Area

* A/C switch circuit
* A/C switch
* A/C amplifier
* Throttle position sensor circuit
* Throttle position sensor
* ECU

 

[whiplash]

Yup, that's the way it should be, also the "new way" found by portez to calibrate the tps.

When jumping the diagnostic box, you want your tps positioned so that you get no codes at idle, ie. with the throttle plate closed, but the slightest push of the throttle, the car should throw the code.

 

[jetjock]

Is code 51 only applicable at idle?

At idle or with the engine off, the car reports no codes.
If I give the engine a quick rev, it reports a code 51 then goes back to normal./QUOTE]

It's only applicable if you have the diag block jumpered. If you're otherwise getting a code 51 you have a problem.

Do not use Porter's method to set the TPS. Toyota's procedure requires using tools to obtain clearances that measure in the thousands of an inch. I guess it doesn't occur to anyone there must be a reason for being that precise. There is. I won't bore you with the details but setting the TPS any other way can result in problems, especially if you live in an emissions state.

 

[supra90turbo]

I guess it doesn't occur to anyone there must be a reason for being that precise. There is. I won't bore you with the details

:biglaugh:

 

[IJ.]

I guess it doesn't occur to anyone there must be a reason for being that precise.

It does to some of us !

 

[jetjock]

A few thou here, a few there...what difference could it possibly make?

 

[IJ.]

JJ: Only takes a few!

The ones that don't get it will drift away from the Mk3 in time.

 

[toml]

Thanks guys - I wasn't trying to set/calibrate the TPS, was just wondering why I got a code51 with the diagnostic port jumpered. I understand now.

 

[jetjock]

JJ: Only takes a few!

The ones that don't get it will drift away from the Mk3 in time.

I agree. Not to mention being precise in everything one does can be beneficial in other aspects of life. For example when I'm machining something I always try to work to a thou or below even if it's not critical. It's just good practice (literally) for when I need to. Course, that doesn't apply to candy-ass CNC types

 

[lagged]

JJ: Only takes a few!

The ones that don't get it will drift away from the Mk3 in time.

we can only hope....