2001 mercury Sable will not start with TPS connected

I have a 2001 mercury Sable 3.0. Two weeks ago, due to vehicle running rough, I change out the TPS and cleaned the IAT. The vehicle has not started since. After ensuring I had spark and fuel, I decided to check the repairs I did earlier. I unplugged the TPS connector and the vehicle started. When I re-plugged the connector, I received a PO122. I have changed that sensor to have the same problem where the vehicle will start if unplugged. What is the calibration procedure for the sensor? Is there a short in the circuit sensor? Not quite sure how to check that for now…..still researching.

Interesting! Moving this one to the Repair section so it'll get more replies.

I'd suggest starting with some voltage measurements with a multimeter at the TPS with the sensor plugged in, KOEO and not starting. Backprobe all three wires and note the readings. Post them here, and we can help you further.

I will readings at first opportunity dependent on weather

found constant voltage at 5 volts
found constant ground
No reading when signal and ground were tested
scan tool reading for tps is constant 93.5. no movement when accelerating

PARKAVE1016 wrote: scan tool reading for tps is constant 93.5. no movement when accelerating

That'd be why it isn't starting. :lol: The car thinks you're flooring the throttle, asking for Clear Flood mode, and turning off the injectors. Does that same 93.5 reading go to zero when you unplug the TPS sensor?

Do me a favor - unbolt the TPS from the throttle body, but leave it electrically connected. Turn the key on and watch the scanner TPS reading while turning the sensor with a screwdriver by hand. Find where the TPS reads something rational (less than 15%, lets say), then try to start it again.

If it now starts, recheck the sensor installation. These can be confusing to install because of how the sensor fits over the throttle pivot shaft. :silly: Been there, done that. If you still can't change the TPS reading, you may have a second bad sensor, or the sensor is getting overextended during installation.

Tyler,
Did as requested and unbolted the TPS from Throttle body. Could not retrieve any reading from Voltmeter. Could have been the probing material being use as I was not able the TPS off the vehicle. Went to local auto store and purchase alligator clips to use with meter. the reading was 4.74 and the spring in the TPS was not working. The first two sensors was made by master parts. This time I purchase a "standard" TPS". the reading was from .32 - 4.35 ohms. I put that on the vehicle and it now starts. Wish I could send you the live data received but the TPS on change every time I press the accelerator. No codes presently. Thank you for the guidance provided. Need to purchase better probing accessories. Thanks again

Well done!

FYI, you may end up with a high idle concern after replacing the TPS on this car, due to the closed throttle position being a 'learned' value. If needed, disconnect the battery for a few minutes and reconnect it to allow the PCM to relearn the closed position.

Does the engine still run rough? Let us know and we can diagnose further if needed.

Great, will do. The rpms are fluctuating 750-950, sounds better than before but will do as suggested. Have not put on road yet, will do tomorrow and let you know. Good to have someone to talk too on these type of problems. Oh…I ordered a back-probing kit. No other problems noted as of yet…. thanks again

PARKAVE1016 wrote: Great, will do. The rpms are fluctuating 750-950, sounds better than before but will do as suggested. Have not put on road yet, will do tomorrow and let you know. Good to have someone to talk too on these type of problems. Oh…I ordered a back-probing kit. No other problems noted as of yet…. thanks again

Tyler is the man!

ScannerDanner wrote: Tyler is the man!

NO you're the man! :lol:

PARKAVE1016, which back probing kit did you get? Just curious to hear what you think about it when it arrives.

Tyler,
Here's the information for my kit....waiting for it to arrive.

Insulation 4mm Banana test lead wire kit pierce spring test probe crocod...
Total: $20.99
Item ID: 232266226376

My vehicle is idling rough (630-777 rpms) and shaking when stopped at light and seems to hesitate on acceleration, maybe the Computer has not relearned the TPS? I should be at 1000 rpm at idle? I currently have a pending PO1151 code and
when I have time and probes, I will be testing the following;
HO2S connector is damaged (check pins for damage, and for moisture)
•HO2S signal circuit open, shorted to ground, shorted to voltage
•HO2S has failed (it may be contaminated with fuel, silicone or water)
There is no air leak that I can find presently.
There is no check engine light

Any suggestions? researching youtube

Sure sounds like you have a misfire on at least one cylinder. A quick power balance test like the one Paul demonstrated in the most recent video would be perfect in your situation:



Even if you get spark out of all six towers, you can still use this test to ID which cylinder isn't contributing.

P1151 may be an O2 problem, or it may be a symptom of the misfire (because most misfires make the O2 read lean). The P1151 by itself won't cause a running issue, so I'd suggest addressing the roughness and hesitation first. Scan data, specifically O2's, fuel trims and Loop Status can also be helpful.

If I'm correct in thinking that the code is the result of a misfire, then you should find a misfire during your power balance test on bank two. Lucky for you, that's the bank closest to the radiator, making testing easy!

Tyler,
Just got off part-time gig but had to do the test in the video. #6 is not firing at all. switch wires same result. looks like I am buying a coil. I did do an ohm test (1 foot wire-4.75) now I need to go to bed and sleep for the mortgage paying job....I will update a first opportunity.....

Good stuff.

Do what you gotta do first! When you get time, let us know how she runs with the new coil.

Tyler,
woke up this morning to a cranking no start condition. battery was weak left on charger. got off early to purchase and replace multipack coil.....same condition cranking no start. already checked TPS , unplugged it, still could not vehicle to start.....will check for spark and fuel tomorrow.... I will ask...any suggestion as to may have happen?

Tyler,
Wanted to update my situation. notice the slow cranking was due to bad starter not battery (12 VOLTS ON METER)...notice smoke when cranking....my other problem is the connector for my coil has or was broken. when I pressed down on the connector the vehicle starts....when I get the chance I will find the nearest junk yard to get one

PARKAVE1016 wrote: Tyler,
Wanted to update my situation. notice the slow cranking was due to bad starter not battery (12 VOLTS ON METER)...notice smoke when cranking....my other problem is the connector for my coil has or was broken. when I pressed down on the connector the vehicle starts....when I get the chance I will find the nearest junk yard to get one

Sorry I missed you yesterday! :blush: Did you get the slow cranking issue fixed? I always wanted to kneecap the engineer that put the oil filter right above the starter.

Well done catching the connector issue, as well. If I had to guess, the power supply pin is either broken internally or is spread open. If you can't find a replacement pigtail, you can take the connector apart and 'repin' it. More work, but it's an option.