16 replies to this topic

[Morgan]

In the midst of fixing the recent acceleration issue in my sisters car, I removed the TPS thinking it was the MAF... Whoops! Reinstalled it but now I'm now getting a CEL and code P0122/P0122 P (Throttle Position Sensor/Switch 'A' Circuit Low Input).

 

I've used my cheap code reader to reset the ECU and also disconnected the battery with no luck on either. The CEL is still there.

 

The car drives and ides fine.

 

After a stack of research, I believe it needs a .45-.55v signal to be correct at idle but I don't know where to put the pokey things on my multimeter to find the signal. Anyone know? Does the CEL automatically disappear when those numbers are found? Or is there a different recalibration sequence I need to go through for the ECU to detect the throttle position?

 

Cheers

 

 

[Morgan]

2.0 MY06 impreza

[bobbyjimmy]

 I removed the TPS thinking it was the MAF... Whoops! 

 

What...

So you took off the part on the right hand side of the throttle body - spring loaded jigger?

#4 in this picture?;

[Morgan]

Its on the left side of the TB (looking at engine). But yeah, that's the part.

[RX25SE]

Morgs,

 

Did  you unplug it with the key on?

 

I can only assume that it has three wires.

One is a power supply, probably a constant 5v. (no change when throttle is moved)

One is earth, should float at about 0.2v (no change when throttle is moved)

 

The last one is the signal (often the middle wire) that, with a 5v reference, will rise to about 4.5v from a 0.5v idle.

 

Check you are getting a voltage change as the throttle is opened. If no you may not have the drive tab of the throttle shaft in the slot in the sensor.

 

Realistically, you can refit the sensor with the screws in the original position. Just look for the witness marks on the sensor.

 

 

 

 

Hang on.

 

Does it have a throttle cable????????????????

 

Code looks like a DBW code??

[bobbyjimmy]

2.0i (SOHC, cable) or 2.0R (DOHC, DBW)?

[Morgan]

It has a cable.

 

Car was not on when sensor removed.

 

the tab should be locked in right. Car drives and idles fine.

 

There's no access to any of the wires when plugged in. I've read I can go straight from the ECU plug but can't find any info on which one to probe at that end.

[RX25SE]

Could you back probe the connector with a pin slid under the grommet?

Best to stay away from the ECU unless you have a reliable pinout diagram.

[Morgan]

Haha yep. That's why I'm here instead

All wires are pretty well covered by the plug. Have just arrived at my mechanic for them to plug in their scanner to have a look

[Morgan]

Could you back probe the connector with a pin slid under the grommet?

Has to be tested with the plug plugged in, right? I can't probe the connector with it removed for the TPS?

[Reevesy]

Has to be tested with the plug plugged in, right? I can't probe the connector with it removed for the TPS?

You should be able to do it with it plugged in. It should squeeze down the side of the wire on the back of the plug and touch the terminal from that side.

[RX25SE]

Yep, plugged in.

Key on, engine off (KOEO)

 

Open and close the throttle to check the readings.

 

 

Scanner will only be good for live data and resetting the code.

[Morgan]

Haha tab was on the wrong side of the bar thingy.

Back on the right way, codes cleared, done.

How embarrassment.

[LPM_B4]

simple fix who cares 

[Morgan]

[RX25SE]

If no you may not have the drive tab of the throttle shaft in the slot in the sensor.

 

 

the tab should be locked in right. Car drives and idles fine.

 

 

Haha tab was on the wrong side of the bar thingy.

 

 

Hahahahaha  

 

Glad its fixed.

 

 

 

 

I'd say the ECU was ignoring the dodgy TPS signal and just using the MAP or MAF (whichever it has) to keep it running sweet.

[Morgan]

Right again, Jase

Weird because I took it off a second time before posting this thread to make sure it was on correctly but clearly I was wrong..

Haha oh well. All good.