Black93lt1

Idling at 2000rpm until I put in gear then drops to 1000. Replaced the TPS and I have tested the connector but not sure if I did it right being that nothing ever changed. Need help!! I hope my ECM isn't bad

Black93lt1

Ok so I figured out how to test the tps...my signal wire stays at .03 from closed throttle all the way to wide open throttle...my power to (grey wire) shows 14.3v same as just the battery, and my power out (black wire) shows 6.1v.

Injuneer

Serious problems.... You should have 5.0V between the gray and black wires, and the signal voltage (blue wire to black wire) should be about 0.6V closed throtlle, and about 4.9V wide open throttle. The black wire is a ground supplied by the ECM.

DTC 22 sets when the signal voltage drops below 0.23V.

Hard to understand how the ECM could supply B+ voltage on the gray wire, unless there is short in the ECM. Alternatively, check the voltage between pins C2 (gray wire) and B18 (black wire), with the harness connector unplugged.

Black93lt1

I show 5.7v between black and grey

GaryDoug

How are you measuring these? The numbers don't add up.

Ignition on, engine off: Put the black probe of the meter on the engine ground somewhere. To test the meter put the red probe to the battery positive terminal, should read about 12-13vdc depending on battery charge.
Move the red probe to the gray wire, should be 4.9-5.1 vdc. Compare readings when TPS is plugged in or unplugged, should change no more than 0.1 vdc. If it changes more, TPS may be shorted. Move the red probe to the TPS black wire, should be 0vdc.
Move the red probe to the TPS blue wire, should be about 0.3-0.9 vdc at idle setting. Move throttle to max, should read 4-5 vdc.

The 5 vdc reference is used for many sensors. I would think if it were way off, there would be more sensor failure codes.

Black93lt1

Meter test showed 13.5

Grounded to grey wire show 5.7 unplugged and plugged

red probe to black wire shows 0.02

Blue wire shows 0.02 with no change to throttle position

GaryDoug

When you checked the meter at the battery, was the engine off and no external charger attached? The 13.5 is high for the battery alone. The 5.7 volts is high also; might be an inaccurate meter. Try the meter's accuracy on a new small 9v alkaline (not carbon zinc) battery. Should be 8.8-9.2 volts.

Looks like the signal wire to the pcm may be shorted to ground somewhere or maybe shorted inside the pcm (less likely).

Black93lt1

Accessory power on with no external charge I'm not at home right now but as soon as I make it home I'll test the meter

Black93lt1

Tested the meter with a 9v battery and it read 10.05v

Black93lt1

Do I need to bring the ecm out to run a new signal wire

GaryDoug

Do this, with the TPS unplugged: Connect your meter to the dark blue wire close to the pcm, with the black meter probe to engine ground. Get a 1.5v AA or AAA battery. Hold the 1.5 v battery with the negative (flat) end to engine ground. Touch the blue wire briefly to the 1.5 v battery positive end (with button). See if the meter reads about 1.5v. If it does, check it again by instead placing any two wet fingers to the positive end of the 1.5v battery and to the blue wire. The reading should rise a tenth of a volt or more from zero. The fingers need to be wet to cause a reading change. It will not shock you. If these tests pass, the pcm is probably ok.

If the 9v battery you chose for checking the meter was an alkaline type, then your meter is reading about 10-12% high. That might explain the 5.7v instead of 5.0v.

Black93lt1

Ok so i placed the negative lead to the alternator bracket and the 1.5v battery (not new) next to it. The red lead to a new signal wire i ran to the pcm and touched them both to the positive side of the 1.5v battery went from reading 0.02 to reading 0.12 touched 2 wet fingers on top of them and it went to 0.13 and yes the 9v was an alkaline

GaryDoug

That's not good. But first, lets review this. Was the original dark blue wire going anywhere except directly to the pcm? In other words, was there still a part of the dark blue wire going into the harness? We want to make sure that nothing else except the battery and meter was possibly connected to the pcm. If there was no possibility of anything else connected, it sounds like the pcm could have a shorted input. The only other possibility is that the dark blue wire is not making good contact with the connector pins in the pcm socket.

Black93lt1

I do believe that the original dark blue wire goes straight to the pcm from the tps...now the end of the wire by the tps connector is hanging out aways so should I first purchase a connector be4 looking to buy a new pcm

GaryDoug

That's not what I meant. We need to make sure there is no short at that wire to another wire in the harness. So you would have to cut it near the pcm to be sure. You can always splice it back later.