P0120 Acura Throttle Pedal Position Sensor/Switch A Circuit Malfunction

Description

OBD-II Trouble Code Description for P0120 Acura

Throttle/Pedal Position Sensor/Switch “A” Circuit

What does this mean?

OBD2 Code P0120 Acura 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 Acura 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 Acura may set. This doesn’t apply to all models.

Symptoms

Possible sumptoms of OBD code P0120 Acura
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 Acura
Potential causes of the P0120 Acura 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 Acura P0122 Acura P0123 Acura P0124 Acura

The OBD2 Code Information Be Applicable For Acura:

2014 Acura RLX,2014 Acura MDX,2013 Acura SUV-X Concept,2013 Acura RDX,2013 Acura NSX Concept,2013 Acura MDX Concept,2013 Acura ILX Endurance Racer,2013 Acura ILX,2012 Acura TL,2012 Acura RLX Concept,2012 Acura NSX Concept,2012 Acura ILX Street Build Concept,2012 Acura ILX Concept,2011 Acura TSX Sport Wagon,2011 Acura TSX Sedan,2010 Acura ZDX,2010 Acura TSX V6,2010 Acura RDX,2010 Acura MDX,2009 Acura ZDX Concept,2009 Acura TSX,2009 Acura TL,2009 Acura RL,2007 Acura TSX,2007 Acura TL Type-S,2007 Acura TL,2007 Acura RDX,2007 Acura MDX,2007 Acura Advanced Sports Car Concept,2006 Acura RDX Prototype,2006 Acura MD-X Concept,2006 Acura Advanced Sedan Concept,2005 Acura TSX A-Spec Concept,2005 Acura TSX,2005 Acura TL,2005 Acura RSX Type-S,2005 Acura RSX A-Spec Concept,2005 Acura RSX,2005 Acura RL with ASPEC Performance Package,2005 Acura RL ASPEC Concept,2005 Acura RL,2005 Acura RDX Concept,2005 Acura NSX,2005 Acura MDX,2004 Acura TL with ASPEC Performance Package,2004 Acura TL 25 Hours of Thunderhill,2004 Acura RL Prototype,2004 Acura 3.2 TL,2003 Acura TL ASPEC Concept,2003 Acura 3.2 CL Type-S,2002 Acura NSX sketches,2001 Acura NSX-T,2001 Acura Integra

Note:

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