Stangski09

iTrader: (10)

Searched for hours, could not find a case like this.

Intermittent code 22:
- minimum air & tps adjusted, both new
- timing set 7* btdc
- FP set at 41.5 psi
- no apparant vac leaks but will check more thoroughly with brake clean

It will idle at 1100 in park some start-ups, and 1500-2000 on other start-ups.
SES will disappear when holding >2500rpms
Basically I have a new built motor, beautiful car, and i cant rid this code 22 nor can I get it to idle well.

Please help

Stangski09

iTrader: (10)

Capped vac line going to booster, and the motor idled the same.
Capped vac line going to the charcoal cannister, and the motor idled the same.

Vader

I'm guessing that the TPS voltage was checked/set at the sensor itself. You may want to go back to the ECM and measure the voltage there. That will include all the connections and circuit resistance. For some reason, the ECM thinks it is reading low voltage, so looking at the ECM may be revealing.

I also suspect you have checked the electrical connector for the TPS and engine/chassis grounds. If not, that could also be helpful.

Stangski09

iTrader: (10)

Yes the tps was adjusted.
Any tips on checking the connections at the ecm?
Ive checked the reference signal at the tps, i have checked resistance

Stangski09

iTrader: (10)

165 ecm.
TPS signal, C13 - 0.50V. Should be 0.54V
TPS reference, C14 - 4.98V, should be 5.00V

The actual signal reading is tad low, but not enough to concern me.
Going to check ecm grounds next.

Update: car will idle at 1200rpm, then it jumps to 1800rpm when it jumps into closed loop (im guessing that it's moving into closed loop)

Stangski09

iTrader: (10)

Checked to make sure car is going into closed loop and it is. (diagnostic mode while motor running).

Stangski09

iTrader: (10)

All ecm grounds are good. (resistance check), grounds on my heads are tight, all other chassis grounds that ive located are good. My engine bay is very clean and im fairly certain I know where all of the grounds are.

Here's a couple photos to entice you guys to chime in!

Vader

Is the 22 still being generated?

Is the ECM reprogrammed with a target idle of 1200 or is it due to some problem?

Stangski09

iTrader: (10)

Code 22 is still coming.
As far as i know the idle was untouched via tune.
Im in the process of getting another data log for pcm4less.

An i had zero issues before this code.
I am very very stumped

Vader

It would seem that the ECM loses communication with the TPS periodically, setting the code. Aside from connections, I'm not sure what to advise. Incidentally, those suspect connections could be inside the ECM as well.

Stangski09

iTrader: (10)

So im probing the wires at the connection to the ecm. I was following a correct 86-98 165ecm pinout. Using a paper clip contacting the metal.
I checked other voltage readings and they all read correctly.
TPS readings were correct - checked with key on.
Grounds were checked for resistance, and the reading stayed at 0.

Really think the ecm is the only thing left?
Because ill grab one off of rock auto and see how she works.

Ps- this ecm was a year old delco reman from GM.

Stangski09

iTrader: (10)

Replaced ecm with a pick n pull one, same issue.
I have a reman on order from rock auto but I doubt anything will change..

Not sure what to do... I think im going to try and chase grounds again, check the commons.

Vader

Even though the TPS was replaced, have you checked its output voltage while rotating the throttle through the full range? Usually an analog meter is best for this to catch any dropouts.

For some reason, the ECM is thinking the TPS is going away (under 200mV) for a few seconds, and it only has the wires and connections to make the assessment.

Stangski09

iTrader: (10)

Where the wires attach to the connectors, could there maybe be an issue there?

Stangski09

iTrader: (10)

I have aluminum heads if that matters.. Im thought they would ground?
So when im checking my grounds with the key on there should be zero voltage running through them right?
But when im checking with an ohm meter shouldnt there be any type of resistance since it's closing a circuit?
Anyways im going to try and jump my grounds on the heads to steel and see how that goes

Stangski09

iTrader: (10)

Update: tried jumping the ecm grounds on the back of my aluminum heads with a wire that extends and grounds to the iron block. Same thing.
So im back to believing that my ecm grounds are grounding, however i would like to know if i am checking them correctly; (1) probe wire with paper clip at ecm connector (2) negative dmm terminal to steel, positive dmm terminal to paper clip (3) and the ohm meter should be moving correct? Because right now my grounds are showing ZERO resistance when I do this

Stangski09

iTrader: (10)

Should i try to change the cts? Since it shares a common ground with the ps

Stangski09

iTrader: (10)

Bump. Hands are still tied.
Changing cts tomorrow, see how that works.
Car idles normally with est disconnected, so im thinking my msd icm may be going bad..

Stangski09

iTrader: (10)

Cts changed out, and still having the exact same issue.
I nee help.
This forum is getting pathetic, no one pikes to GIVE advice, they just take it.

Firechicken86

iTrader: (1)

I've got the same code, and have no idea what's causing it

Stangski09

iTrader: (10)

Changed out all of my battery cables,
1/0 batt positive
1/0 batt negative
1/0 alt power
1/0 batt negative to body ground


Im at a loss here...

Firechicken86

iTrader: (1)

I think my problem lies with a bad ecm, I checked the voltage going into from the wire that goes to the tps and it reads .03V so I'm going to try and swap in a new ecm and see if that fixes my code 22. Have you tried taking out your IAC and cleaning it with carb cleaner? clogged up IAC's is a culprit for high idling. I have no idea what could be causing your code 22 though.

ASE doc

I would bet that most likely you have a short to ground in the signal circuit. An open sensor ground WILL NOT cause this code. An open ground circuit, or open signal circuit will cause code 21(open signal circuit will cause TPS reading of 5v due to diagnostic resistor in ECM). Only an open reference circuit or short to ground in signal circuit will cause code 22. It may be an intermittent short or open. To find the cause, use your DVOM to monitor the signal voltage while wiggling the ECM harness between the TPS and ECM. Watch for signal voltage to drop off. Then, disconnect the ECM connectors and the TPS and using the ohms scale, or continuity function, connect one lead to the disconnected signal circuit and the other lead to the ground circuit and repeat the wiggle test looking for continuity. There should be no continuity whatsoever between the two circuits. If no trouble found, repeat the wiggle test on the 5v ref. circuit with the system reconnected and the key on. Look for voltage to drop off.

BTW, I appreciate the cleanliness of your engine bay. I strive for the same level of cleanliness in my own.

Firechicken86

iTrader: (1)

Don't mean to veer off topic but where are the grounds for the tps located? everyone says on the back of the cylinder head but I can't find it for the life of me

ASE doc

The ground for the TPS comes from the ECM, as do all of the sensor grounds. The ECM grounds are at the rear of the cylinder heads.

EDIT: I just realized that this may be a confusing statement. The sensor grounds all originate at the ECM. There may be one or two ground circuits that are shared by more than one sensor. The grounds for the ECM connect at the rear of the cylinder heads. Refer to a wiring diagram for your year and model of car.

ASE doc

I must apologize for giving bad information. The diagnostic resistor on the TPS signal circuit does not go to 5v but rather to ground. This means that an open TPS signal circuit will read 0v, not 5v. Therefore, code 22 can be caused by an open in the signal circuit.

Stangski09

iTrader: (10)

Firechicken86, if youre tps is reading low try adjusting it, and if you can not get it adjusted youre looking at a bad tps.

And clearly my iac is not dirty because it is brand ****ing new. As are my spares that ive tried.

ASE doc, thanks for the tips on checking the tps wiring, I have checked it but ill definitely check it again.

Firechicken86

iTrader: (1)

Are you sure it would be from a bad tps and not a bad ecm? I tried reading the voltage from the grey wire on the ecm going to the tps and it read .03V even after adjusting it.

ASE doc

.03v on the gray wire at the ECM is either a poor connection at terminal C14, or a bad ECM. Be sure to verify power and ground before condemning an electronic module.

Stangski09

iTrader: (10)

ASE doc I tried the wiggle test and i had no variance in voltage.
Now i tried the ohm test between the ground wire and signal wire, there was movement on the ohm meter; therefore there was contInuity.
What is the fix?

Stangski09

iTrader: (10)

Just an update here:
- before I stored her for winter I ran new wiring including connector from the tps to the ecm. Still had the issue.
- replaced ecm with a reman, same problem.

However when I parked it I tried grounding the ground wire that is part of the dual electric fan harness. Because I realized that relay in the harness was grounded
I REMOVED THE DUAL FAN HARNESS B DISCONNECTING IT AT THE CONNECTOR NEAR THE RAD LAST YEAR.
So then I quickly fired it up and it was idling smoothly at 800ish and not climbing slowly to 2000 like it liks too, but I was still getting a code even after I disconnected the battery however I did not reset my min air and tps voltage..
Does this sound like it could be the culprit?