Chrysler P0120 Throttle Pedal Position Sensor/Switch A Circuit Malfunction

Description

OBD-II Trouble Code Description for P0120 Chrysler

Throttle/Pedal Position Sensor/Switch “A” Circuit

What does this mean?

OBD2 Code P0120 Chrysler definition:
The TPS (Throttle Position Sensor) is a potentiometer that is mounted to the throttle body. It detects the throttle blade angle. As the throttle blade moves, the TPS sends a signal to the PCM (Powertrain Control Module). Usually a three wire sensor: A 5 volt reference from the PCM to the TPS, a ground from the PCM to the TPS, and a signal return from the TPS to the PCM.

The TPS sends the throttle position information back to the PCM on this signal wire. When the throttle is closed the signal is near .45 volts. At WOT (Wide Open Throttle) the TPS signal voltage will approach a full 5 volts. When the PCM sees a voltage that is outside of normal operating range, P0120 Chrysler will set.

NOTE: The PCM knows that any large change in throttle position means a cooresponding change in manifold pressure (MAP). On some models the PCM will monitor MAP and TPS operation for comparison. Meaning that if the PCM sees a large percentage change in throttle position, it expects to see a cooresponding change in manifold pressure and vice versa. If it doesn’t see this comparitive change, P0120 Chrysler may set. This doesn’t apply to all models.

Symptoms

Possible sumptoms of OBD code P0120 Chrysler
Potential symptoms include:

MIL (Malfunction Indicator Lamp) illumination
Misfiring at idle or at highway speed
Poor idle quality
Possibly won’t idle
Possibly starts and stalls

Causes

Possible causes of OBD code P0120 Chrysler
Potential causes of the P0120 Chrysler code include:

Sticking throttle return spring
MAP or TPS connector corrosion
Misrouted harness causing chafing
Bad TPS
Bad PCM

Possible Solutions

If you have access to a scan tool, with KOEO (Key on engine off) observe the TPS voltage. With throttle closed, voltage should be about .45 volts. It should gradually sweep upwards to approximately 4.5 to 5 volts as you depress the throttle. Sometimes only a scope can capture an intermittent glitch in the TPS signal voltage. If you notice a glitch in the TPS sweep voltage, replace the TPS.

NOTE: Some TPS sensors require fine adjustment. If you aren’t comfortable with using a DVOM (Digital Volt Ohm meter) to adjust the new TPS, then it’s best to take the vehicle to a shop. If the voltage is not .45 volts (+or- .3 volts or so) with the throttle closed or if the reading is “stuck” then unplug the TPS connector. With KOEO check for 5 volts reference voltage present at the connector and a good ground. You can check the signal circuit for continuity by jumping a fused wire between the ground circuit of the TPS connector and the signal circuit. If the TPS reading on the scan tool now reads zero, then replace the TPS. However if that doesn’t change the reading to zero, then check for an open or a short on the signal wire and if none is found, suspect a bad PCM. If manipulating the TPS wiring harness causes any change in idle, then suspect bad TPS.

Related Codes

P0121 Chrysler P0122 Chrysler P0123 Chrysler P0124 Chrysler


The OBD2 Code Information Be Applicable For Chrysler:

2013 Chrysler Town and Country S,2013 Chrysler 300 Motown Edition,2013 Chrysler 300 Glacier,2012 Chrysler Ypsilon,2012 Chrysler Delta,2012 Chrysler 300 SRT8,2012 Chrysler 300 Luxury Series,2012 Chrysler 300C,2011 Chrysler Town and Country,2011 Chrysler 300,2011 Chrysler 200 S,2011 Chrysler 200 Convertible,2011 Chrysler 200,2009 Chrysler GEM Peapod,2009 Chrysler 200C EV Concept,2008 Chrysler ecoVoyager Concept,2008 Chrysler Town and Country,2008 Chrysler Sebring Convertible,2008 Chrysler EV Concept,2008 Chrysler 300C UK Version,2008 Chrysler 300C Touring UK Version,2008 Chrysler 300C Touring SRT UK Version,2008 Chrysler 300C SRT UK Version,2007 Chrysler Sebring UK Version,2007 Chrysler Sebring,2007 Chrysler Pacifica,2007 Chrysler PT Street Cruiser Pacific Coast Highway,2007 Chrysler Nassau Concept,2007 Chrysler Crossfire UK Version,2007 Chrysler Crossfire Roadster UK Version,2007 Chrysler Aspen,2006 Chrysler Imperial Concept,2006 Chrysler 300C SRT8 Touring,2006 Chrysler 300C Heritage Edition,2005 Chrysler Town and Country,2005 Chrysler PT Cruiser Convertible,2005 Chrysler Firepower Concept,2005 Chrysler Crossfire SRT6 Roadster,2005 Chrysler Crossfire SRT6,2005 Chrysler Crossfire Roadster,2005 Chrysler Akino Concept,2005 Chrysler 300C Touring,2005 Chrysler 300C SRT8,2005 Chrysler 300C,2005 Chrysler 300,2004 Chrysler Pacifica,2004 Chrysler ME FourTwelve Concept,2004 Chrysler Crossfire,2003 Chrysler Airflite Concept,2003 Chrysler 300M,2003 Chrysler 300C Touring Concept,2003 Chrysler 300C Concept,2002 Chrysler Pacifica Concept,2002 Chrysler California Cruiser Concept

 

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