Description
OBD-II Trouble Code Description for P0121 Pontiac
Throttle/Pedal Position Sensor/Switch “A” Circuit Range/Performance
What does this mean?
OBD2 Code P0121 Pontiac definition:
The Throttle position sensor is a potentiometer that measures the amount of throttle opening. As the throttle is opened, the reading (measured in volts) goes up. The powertrain control module (PCM) supplies a 5 Volt reference signal to the throttle position sensor (TPS) and usually a ground also. A general measurement is: at idle = .5 Volts; full throttle = 4.5 Volts. If the PCM detects that the throttle angle is greater or less than it should be for a specific RPM, it will set this code.
Symptoms
Possible sumptoms of OBD code P0121 Pontiac
Symptoms of a P0121 Pontiac trouble code could include: Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light) Intermittent stumble on acceleration or deceleration Blows black smoke on acceleration No start
Causes
Possible causes of OBD code P0121 Pontiac
A code P0121 Pontiac may mean that one or more of the following has happened: TPS has intermittent open or short internally Harness is rubbing and causing an open or short in the wiring Bad connection at the TPS Bad PCM (less likely) Water or corrosion in connector or sensor
Possible Solutions
1. If you have access to a scan tool, see what the idle and WOT (wide open throttle) readings are for the TPS. Check if they’re close to the specifications mentioned above. If not, then replace the TPS and re-check. 2. Check for an intermittent open or short in the TPS signal. To do that, you can’t use a scan tool. You’ll need an oscilliscope. The reason is because scan tools take samplings of many different readings over just one or two data lines and can miss an intermittent drop out. Hook up your oscilliscope and watch the signal. It should sweep up and down smoothly with no drop outs or spikes. 3. If no problems were noticed, perform a wiggle test. Do this by wiggling the connector and harness while watching the pattern. Does it drop out? If so, replace TPS and re-check. 4. If you have no TPS signal, check for 5 Volt reference at the connector. If it’s present, check the ground circuit for open or shorts. 5. Make sure the signal circuit isn’t 12V. It should never have battery voltage. If it does, trace circuit for short to voltage and repair. 6. Look for any water in the connector and replace TPS as necessary.
The OBD2 Code Information Be Applicable For Pontiac:
2010 Pontiac G8,2009 Pontiac G8,2009 Pontiac G6 ,2009 Pontiac G3,2008 Pontiac G8,2007 Pontiac Solstice SD-290 Concept,2007 Pontiac Solstice GXP,2007 Pontiac G6 GXP Show Car,2006 Pontiac Torrent,2006 Pontiac Solstice,2006 Pontiac Montana SV6,2006 Pontiac GTO,2006 Pontiac G6 GTP Coupe,2006 Pontiac G6 GTP Convertible,2005 Pontiac Vibe GT,2005 Pontiac Montana SV6,2005 Pontiac Grand Prix,2005 Pontiac Grand Am GT Coupe,2005 Pontiac GTO,2005 Pontiac G6 GT,2004 Pontiac Grand Prix GTP,2004 Pontiac Grand Am GXP,2004 Pontiac GTO 5.7,2004 Pontiac GTO,2004 Pontiac Bonneville GXP,2004 Pontiac Aztek Rally,2003 Pontiac Vibe GT,2003 Pontiac Vibe,2003 Pontiac Sunfire Coupe,2003 Pontiac Montana Thunder,2003 Pontiac Grand Prix,2003 Pontiac Grand Am SE Sedan,2003 Pontiac G6 Concept,2003 Pontiac Aztek,2002 Pontiac Sunfire GXP,2002 Pontiac Sunfire American Tuner,2002 Pontiac Solstice Concept,2002 Pontiac REV Concept,2002 Pontiac Grand Prix GXP,2002 Pontiac Grand Prix G-Force Concept,2002 Pontiac Firebird Trans Am Edition,2001 Pontiac Vibe GT,2001 Pontiac Vibe,2001 Pontiac Sunfire HO,2001 Pontiac Sunfire Accessorized,2001 Pontiac Montana,2001 Pontiac Grand Prix
Note:
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