So this popped up on me today. Supposedly a TPS. The reason I looked is I can tell the old girl started idling ever so slightly, barely, noticeably rough.

the type of change in idle that only the person who drives the vehicle everyday, and knows each sound the vehicle makers would notice. So all in all not bad. But still, I like to get ahead of things.

my question is, can the TPS cause a little rough idle? And maybe even cause the engine to feel like it had a miss, like when a coil is cooked?

because I’m mentally scarred from my last coolant leak. It was the hose that is at the upper passenger side of the firewall, above the coils on that bank of the engine. The coolant messed them up and it was a great time replacing them and the plugs lol.

And of course I smell a faint smell of coolant. I can’t find a leak anywhere through visual inspection, so I have a pressure tester coming in the mail today.

so could it be a coincidence that I smell coolant and am experiencing a little rough idle? Could it really be the TPS?

oh, I found this on my OBD:

 

The code tells you the TPS is open circuit (high).
You don't have to remove it if an Ohm Meter test shows it good and smooth in operation but look for the plug to be open or the harness.
No the motor won't be rough at idle but not accelerate normal or even upshift or down shift correctly because the PCM has to know what you're doing with the foot throttle.
In the video, the part on the side blocking the lower screw is the EGR vacuum regulator.
Under the round cap is an air filter.
The cap has to be pried off because there are locking lugs that hold it on, not threads.
The part is removable. Un plug the connector and take the hoses off and unbolt the the plate.

 

awesome. Thank you!

 

Ok. Got it all back together. It cranks but won’t start.


edit

ok, so I noticed the new one wasn’t in the same position as the old one. The little thing with the two teeth on it. So I just manually put it in the same position and note it works.

but now I have a check engine light on.

code is P0122$10




i cleared it. I guess I’ll see if it comes back. Other than that it’s running great. It definitely needed to be changed.

 

Started it up this morning. The check engine light came back on.

is this new tps bad? How do I check it? It feels like it’s running fine. Better than before.


new development. It won’t down shift while driving when I attempt to pass. Doesn’t matter If I mash my foot to the floor

 

If you have a 122 code, the circuit is now shorted.
With that condition, it will affect Trans shifting.
The PCM still cannot tell what the throttle is doing for the decision on how to control the transmission.
Always possible the TPS sensor is faulty but look closely at the wire harness.
The TPS is a 3 lead device powered by 5 volts to ground with the third lead the signal back to the PCM to indicate throttle angle.
Test it with an OHM Meter function to see if the device is shorted between any terminal. It is a variable resistance.
Keep in mind if you test the third lead to one of the terminals it will show low resistance until the throttle moves the sensor position.
With the ignition on, there should be about 5 volts between two of the leads one being the black ground lead. Do this test with the connector unplugged.
My hunch is the wire harness has a fault at some location for it to change from open to shorted.
Good luck.

 

ok. I think I did this test correctly. It looks like 4.99v

 

The voltage it fine. Only comment is your test prods are in reversed but not an issue. The meter still reads but with a >minus sign< before the reading.
Looks like the TPS sensor is faulty since you can't plug up to it wrong because the plug is keyed to prevent it.
Only other possibility is the signal lead back to the PCM may be open or grounded.

 

It was a bad “new” part. Got a replacement and it’s fine, except now I have another issue which I suspect may be related. I dunno. I’ll start a new thread.