What are the symptoms of a bad tps?

blubullett

Member
Jun 22, 2006
535
6
18
Modesto, CA
I was driving my car today and it started surging really bad. It was almost impossible to keep it running and it was bucking like crazy. I pulled over and checked the codes and it said tps and maf signals dont match up. I dont remember the code number. I cleared them and started my car up again and it idled ok. I put it in gear and started to drive away and it just about dies. Now it will idle fine but if you try to drive it it tries to die. It also isnt throwing any codes anymore. Any ideas? Bad maf(its new)? Bad tps?
 
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could be a bad TPS.....what are you running for a MAF? Is it a stocker? If it's an aftermarket one, is the car tuned properly? If you have a standard Multimeter, you can read out the TPS to see if thats the problem. let me look it up for you....
 
DH: Throttle Position (TP) Sensor DH: Introduction

--------------------------------------------------------------------------------

DH1 KOEO AND KOER DTC P1124: CHECK FOR OTHER DTCS
Check for DTC P1400 or P0405 in KOEO or KOER Self-Test.
Is KOEO or KOER DTC P1400 or P0405 present with KOEO DTC P1124?
Yes No
RETURN to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts for DTC P1400 or P0405. KEY OFF. GO to DH2 .

DH2 CHECK FOR STUCK THROTTLE PLATE OR LINKAGE
Visually inspect the throttle linkage and throttle plate for binding or sticking.
Verify the throttle plate and linkage is at closed throttle position.
Does the throttle move freely and return to closed throttle position?
Yes No
Throttle plate and linkage are OK. GO to DH8 . REPAIR as necessary.

DH3 DTC P1120: CHECK TP CIRCUIT FOR FRAYED WIRES OR CORROSION ON CONNECTORS
Key off.
Complete a visual inspection of pins on harness connector at the TP sensor for corrosion.
Complete a visual inspection of the harness wires between the TP sensor and the PCM for insulation fraying and corrosion.
Is a fault present?
Yes No
REPAIR as necessary. GO to DH4 .

DH4 CHECK FOR STUCK TP SENSOR
Key on, engine off.
Access TP PID (TP V PID).
Slowly move throttle from closed throttle position to wide open throttle position and observe the TP PID (TP V PID).
While opening the throttle, is the TP PID (TPV PID) reading below 9.85% (0.49 volt)?
Yes No
KEY OFF. GO to DH5 . GO to DH20 .

DH5 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS TO TP SENSOR
Disconnect TP sensor.
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
KEY OFF. GO to DH6 . GO to C1 .

DH6 CHECK TP CIRCUIT FOR OPEN IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect PCM.
Measure resistance of TP circuit between PCM harness connector pin and TP harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to DH7 . REPAIR open circuit.

DH7 CHECK TP SENSOR VOLTAGE TO PCM
Reconnect PCM and TP sensor.
Start engine and idle for 2 minutes.
Access TP PID (TP V PID).
Slowly open the throttle from closed position and observe PID(s).
Is TP PID (TP V PID) reading at any time between 3.42-9.85% (0.17-0.49 volt)?
Yes No
REPLACE TP sensor. If DTC P1120 is still present, GO to DH20 .

DH8 DTC P0123 OR P1124: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING
Disconnect TP sensor.
Key on, engine off.
Access TP PID (TP V PID).
Is TP PID (TP V PID) less than 3.42% (0.17 volt)?
Yes No
GO to DH9 . KEY OFF. GO to DH10 .

DH9 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS AT TP SENSOR
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
REPLACE TP sensor. GO to C1 .

DH10 CHECK TP CIRCUIT FOR SHORT TO VREF OR VPWR IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect PCM.
Measure resistance between TP and VPWR circuits at the PCM harness connector.
Measure resistance between TP and VREF circuits at the PCM harness connector. (For 150 PIN PCM and 122 PCM PIN, measure to both VREF pins.)
Is each resistance greater than 10,000 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.

DH11 DTC P0122: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING
Note: An intermittent fault can cause a Continuous Memory DTC P0122. If a Continuous Memory DTC P0122 is still present after DH11 through DH14, GO to Z1 .

Disconnect TP sensor.
Jumper VREF circuit to TP circuit at the TP sensor harness connector.
Key on, engine off.
Note: If any scan tool communication concern exists, remove jumper and GO to DH14 .

Access TP PID (TP V PID).
Is TP PID (TP V PID) greater than 93% (4.65 volts)?
Yes No
REPLACE TP sensor. REMOVE jumper. GO to DH12 .

DH12 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
KEY OFF. GO to DH13 . GO to C1 .

DH13 CHECK TP SENSOR CIRCUIT FOR OPEN IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect PCM.
Measure resistance of TP circuit between PCM harness connector pin and TP sensor harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to DH14 . REPAIR open circuit.

DH14 CHECK TP CIRCUIT FOR SHORT TO PWR GND OR SIG RTN IN HARNESS
Disconnect PCM.
Disconnect scan tool from DLC.
Measure resistance between TP and PWR GND circuits at the PCM harness connector.
Measure resistance between TP and SIG RTN circuits at the PCM harness connector.
Are both resistances greater than 10,000 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.

DH15 DTC P1121 OR P0068: CHECK RATIONALITY OPERATION BETWEEN TP AND MAF SENSORS
Attempt to start engine.
Does the engine run?
Yes No
GO to DH16 . CHECK for major leaks, cracks, and openings between MAF sensor and throttle body. If OK, GO to A1 .

DH16 CHECK MECHANICAL OPERATION OF TP SENSOR
Key on, engine off.
Access TP PID (TP V PID).
Slowly move throttle from closed throttle position to wide open throttle position.
Observe and record the TP PID (TP V PID).
While opening and closing the throttle, is there a change in the TP PID (TP V PID) between 9.85% and 93% (0.49 and 4.65 volts)?
Yes No
GO to DH17 . REPLACE TP sensor. VERIFY a symptom no longer exists.

DH17 CHECK TP SENSOR SIGNAL HIGH VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE
Key on, engine running.
Drive vehicle, exercising the throttle and TP sensor while accessing PIDS.
Access TP PID (TP V PID) and LOAD PID and record readings.
Is TP PID (TP V PID) greater than 49.02% (2.44 volts) and the LOAD PID reading less than 30%?
Yes No
LISTEN for air noise around MAF sensor and throttle body while engine is running. REPAIR if necessary. Otherwise, GO to HU1 for air restriction. If OK, REPLACE the TP sensor. GO to DH18 .

DH18 CHECK TP SENSOR SIGNAL LOW VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE
Note: If the vehicle is a no start, GO to A1 .

Drive vehicle exercising the throttle and TP sensor near higher gears (preferably overdrive) while accessing PIDS.
Access TP PID (TP V PID) and LOAD PID.
Is TP PID (TP V PID) reading less than 4.82% (0.24 volts) and the LOAD PID reading greater than 55%?
Yes No
TIGHTEN TP sensor to throttle body if necessary. CLEAR Continuous Memory DTCs. DRIVE vehicle exercising the throttle. If Continuous Memory P1121 is now present, REPLACE MAF sensor. Unable to identify the fault at this time. If vehicle is still a No Start, GO to A1 .

DH20 CONTINUOUS MEMORY DTCS P1120 OR P1125: CHECK FOR TP CIRCUIT INTERMITTENT SIGNAL
Start engine and bring to idle.
Run throttle up to 1500 rpm for 5 seconds.
Access TP PID (TP V PID) for a fault indication while completing the following:
Lightly tap on TP sensor and wiggle harness connector to simulate road shock.
Is TP PID (TP V PID) changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes No
INSPECT the TP sensor connector. If OK, REPLACE the TP sensor. KEY OFF. GO to DH21 .

DH21 CHECK TP SENSOR HARNESS FOR INTERMITTENT OPENS OR SHORTS
Again access the TP PID (TP V PID).
Key on, engine off.
Complete the following:
Grasp the vehicle harness closest to the TP sensor connector.
Shake and bend a small section of the harness all the way to the dash panel.
Wiggle, shake and bend the harness from the dash panel to the PCM.
Is TP PID (TP V PID) reading changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes No
ISOLATE and REPAIR as necessary. Unable to duplicate or identify fault at this time.GO to Z1

DH22 DTC P0121: ISOLATE BINDING OR STICKING CONCERN
Disconnect accelerator cable and speed control cable from throttle body linkage.
CAUTION: Do not attempt to clean the throttle bore and plate area. Cleaning will damage the throttle body assembly.

Note: Sticking or binding condition can either appear within cables or throttle body assembly.

Rotate throttle body linkage.
Does the throttle body rotate freely without a sticking, binding or grabbing condition?
Yes No
INSPECT cable(s). REPAIR as necessary. RERUN Quick Test. If the DTC P0121 is still present, GO to DH23 . REPLACE throttle body assembly.

DH23 CHECK FUNCTIONALITY OF THE THROTTLE POSITION SENSOR
Key on.
Access TP V PID.
From closed throttle, slowly begin to press accelerator to wide open throttle.
Did the TP V PID display a smooth reading during accelerator movement?
Yes No
VERIFY a symptom no longer exists. KEY OFF. REPLACE TP sensor.
 
It's actually pretty rare for a TPS to malfunction. It is not uncommon on these cars for the RPM's to "hang" when the clutch is pushed in. This promotes catalytic converter longevity and reduces emissions. But there are quite a few people that have made or ordered a specially made gasket that goes in between the IAT and the plenum.

Do a search for "hanging RPM's" or something to that effect.
 
Dan thanks for the post. My multimeter is at work but ill bring it home tomorrow. It is an aftermarket maf (sct 2400) and i dont really see it going bad that quickly. My tune has been rich and i was going to get it retuned on wensday but the shop is 50 miles away and i dont feel like having it towed that far. If anybody has any other guesses im open to suggestions. As long as it isnt "is your maf plugged in?". Thanks guys.
 
I unplugged the maf and it idles ok but you have to keep your foot on the gas a tiny bit to keep it going. Plugged it back in and it runs like **** and spits crap out the exhaust. I tried reflashing the computer with my tune and it ran ok for a min. then i turned the ac on to give it a load and it started sputtering again. Turned the ac off and it still sputters.
 
did you try to disconnect the batter for 10-15 min and clear the kepp alive memory(KAM). I would do that and try it, if it sill idles but you have to give some gas to keep runing, try tapping on the IAC and see if that helps. My IAC used to stick when it was moist out. I removed it a cleaned and no more problems
 
If anybody has any other guesses im open to suggestions. As long as it isnt "is your maf plugged in?". Thanks guys.

If your car stalled on the highway, and you were stranded, if the tow truck guy asked if you were out of gas, would you disregard his idea as invalid, and send him on his way, just because it's a simple thing to ask? Someone throwing out the idea of "how about changing the wheel from square to round" was revolutionary, yet incredibly simple.

I've seen I don't know how many threads, where people threw all kinds of money in to replacing parts, only to discover a loose vacuum line, a disconnected wiring harness, or something simple like that.

But your point is taken. I'll remember from now on not to give suggestions in future threads you create.
 
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If your car stalled on the highway, and you were stranded, if the tow truck guy asked if you were out of gas, would you disregard his idea as invalid, and send him on his way, just because it's a simple thing to ask? Someone throwing out the idea of "how about changing the wheel from square to round" was revolutionary, yet incredibly simple.

I've seen I don't know how many threads, where people threw all kinds of money in to replacing parts, only to discover a loose vacuum line, a disconnected wiring harness, or something simple like that.

Amen brother. Something needs to done about these "attitudes" on here.

But your point is taken. I'll remember from now on not to give suggestions in future threads you create.

Don't let these poor unappreciative attitudes discourage you. You seem to be an intelligent rational person and based upon reading some of your posts, you seem to have a good understanding of cars.

blubullet, I agree with svttech that it sounds like you may have a bad vacuum leak. If the PCM is adding that much fuel, that is a sign of a significant vacuum leak. Additionally if the PCM is adding an abnormal amount of fuel to compensate for a vacuum leak, you could have a few fouled plugs as well. Might not hurt to check them.
 
If anybody has any other guesses im open to suggestions. As long as it isnt "is your maf plugged in?". Thanks guys.


Some times it can be the simple things, I would not overlook them.

Did you get the CEL to come back on? If so did you run the code yet? If you do get the EXACT code number.

All you can do untill you get that code is run the engine and feel and look around for loose or disconnected vacumm lines. Most likely it is a large vacumm leak.
 
code #1121- tps inconsistant with maf. Sorry sgarlic didnt mean to offend you. I just assume that if your working on your own car and posting on here you would already know to check for things like that. Ill try not to be such a smartass in the future. But anyways, it runs better with the maf unplugged. Also if you reset the computer (unplugging the battery) it will run better untill it gets a load, then its messed up till you reset it again.

Also p0102 mas vol ar flo cir lo I
 
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Amen brother. Something needs to done about these "attitudes" on here.



Don't let these poor unappreciative attitudes discourage you. You seem to be an intelligent rational person and based upon reading some of your posts, you seem to have a good understanding of cars.

blubullet, I agree with svttech that it sounds like you may have a bad vacuum leak. If the PCM is adding that much fuel, that is a sign of a significant vacuum leak. Additionally if the PCM is adding an abnormal amount of fuel to compensate for a vacuum leak, you could have a few fouled plugs as well. Might not hurt to check them.
Vacuum leak at the egr solenoid im bettin lol. Old thread but i had the same problem. Turned out to be a vacuum leak that was applying vacuum to the egr at idle causing a poor idle and surging. Changed the egr solenoid and no more vacuum at the egr meant no more leak. Fixed my lean condition and surging idle problems. Just a thought
 
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