P0122 TPS - Replaced, No Dice, Now What??

Last week I pulled an EGR P1406 (which I get intermitently, I've cleaned, cleaned, cleaned, if I reset it with my scanner it goes away for several days) AND a P0122. I've driven it about 1000 miles since I put a new-used tranny in it. The shift from 1st to 2nd got bang-hard, and it didnt' seem like the TC was locking up. I cleared the codes with the scan tool and they went away for about a week. Yesterday the P0122 hit again on the way to work. I picked up a new TPS ($45) and stood out in the rain to install it, and cleared the code. This am I get 6 miles from home and the !@@##$%% SES comes on and bang-shift starts again. P0122 and P1406.:banghead:

Any ideas? I'm suppsed to take a 3 hour trip tomorrow to a family reunion....

What year and what engine?
Is the tps sensor adjustable?
On the TPS sensor you need to run a voltage test on it.
On the EGR valve code you need a engine capable scanner to test or check it.
Pull egr valve and check for a carbon ball under plunger.
If it is clean it may be time for a new egr valve.
MT

If your getting the hard shift, the PCM is commanding full line pressure to the transmission as a result of some problem, most likely because of the bad TPS signal. Don't drive it with full line pressure to long, or you'll damage/destroy your transmission. Check connections to the TPS, is the connector at the TPS good? Bend the prongs on the TPS a bit and reconnect it, this will ensure there is no connection issue at the sensor. Other than that, get a scanner on there and see whats happening, watch the TPS output is it smooth, is it intermitent, etc, etc.

It's a 96 S10 4x4, 4.3L, W code

TPS sensor not adjustable. EGR has been cleaned well.

I had NO IDEA that the bad TPS could cause tranny damage. That's just great. I just put the tranny in 1000 miles ago, what a job and $$$, if the TPS f's up the tranny I'm going to drive it into the Niagara River.

Check your voltage readings on TPS and for a good ground and plugin connections.
The key on power to it voltage should be around .5 volts.
out put voltage .5 to 1.0 at idle closed throttle and swing to 4.5 to .5 volts open throttle with no drop outs..

This may seem like a stupid question, but how does one test the output voltage of the TPS with the plug/connector hooked into it?

I understand how you can test the voltage coming from the ECU, with the connector unplugged from the TPS.

Where on the ECU do TPS wires connect?

thanks very much

This may seem like a stupid question, but how does one test the output voltage of the TPS with the plug/connector hooked into it?

I understand how you can test the voltage coming from the ECU, with the connector unplugged from the TPS.

Where on the ECU do TPS wires connect?

thanks very much

Check tps voltages with the tps pluged in and key on ign.

Get that part checked first.
If you have to go to the pcm you will need a scanner to see what the pcm is reading.
Check tps voltage at sensor and post back voltage readings.
MT

To check TPS voltage, you need to get a voltmeter and stab the wire with the leads of the voltmeter. You need to, as MT explained, test with key on, this will give you a reading and you'll kow where you are at that point.

Well I checked the reference voltage with the connector off, key on and got 5 volts. I wiggled and jiggled the wire and it stayed steady 5 volts. I got 5 volts when I was grounded to the block, and when I was grounded to the connector ground.

I wasn't aware you had to stab the wires thru the insulation to get the connector-on readings. I'm going to have to sharpen my meter wire tips. I will try that this evening.

The P0122 last hit on 7/19, I drove it 7/22-7/25 no issues, this am it hit again on the way to work again, practically the same place as last week. Trying to find an intermittent fault like this is aggravating as hell.

Well I checked the reference voltage with the connector off, key on and got 5 volts. I wiggled and jiggled the wire and it stayed steady 5 volts. I got 5 volts when I was grounded to the block, and when I was grounded to the connector ground.

I wasn't aware you had to stab the wires thru the insulation to get the connector-on readings. I'm going to have to sharpen my meter wire tips. I will try that this evening.

The P0122 last hit on 7/19, I drove it 7/22-7/25 no issues, this am it hit again on the way to work again, practically the same place as last week. Trying to find an intermittent fault like this is aggravating as hell.


5 volts to it is the key on power.
You need to look at the output voltage to pcm.

You need to look at the output voltage to pcm.

Yes I am aware of that. I just didn't know how to actually DO it - now that I understand I must jab the test leads thru the wire insulation, I will be doing that this evening.

And I'll wager it will be just fine....in keeping with the sporadic nature of this fault.