Description
OBD-II Trouble Code Description for P0121 Buick
Throttle/Pedal Position Sensor/Switch “A” Circuit Range/Performance
What does this mean?
OBD2 Code P0121 Buick 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 Buick
Symptoms of a P0121 Buick 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 Buick
A code P0121 Buick 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 Buick
2013 Buick Verano Turbo,2013 Buick Riviera Concept,2013 Buick Encore,2013 Buick Enclave,2012 Buick Verano,2012 Buick Regal GS,2011 Buick Regal,2011 Buick LaCrosse GL Concept,2011 Buick GL8,2011 Buick Envision Concept,2010 Buick Regal GS Concept,2010 Buick LaCrosse,2009 Buick Business Concept,2008 Buick Lucerne Super,2008 Buick LaCrosse Super,2008 Buick LaCrosse CXS,2008 Buick Invicta Concept,2008 Buick Enclave,2007 Buick Riviera Concept Coupe,2006 Buick Terraza,2006 Buick Rendezvous CXL,2006 Buick Rainier CXL,2006 Buick Lucerne CXS,2006 Buick Enclave Concept,2005 Buick Terraza CXL,2005 Buick Royaum,2005 Buick Rendezvous CX,2005 Buick Park Avenue,2005 Buick LeSabre Celebration Edition,2005 Buick LaCrosse CXS,2005 Buick LaCrosse CSX,2005 Buick Century,2004 Buick Velite Concept,2004 Buick Rendezvous Ultra,2004 Buick Regal Abboud GS,2004 Buick Rainier,2004 Buick Park Avenue Ultra,2003 Buick Rendezvous,2003 Buick Park Avenue Ultra,2002 Buick Rendezvous,2002 Buick Regal,2002 Buick LeSabre Custom,2001 Buick Regal,2001 Buick Park Avenue Ultra,2001 Buick Park Avenue,2001 Buick LeSabre,2001 Buick Blackhawk Concept,2001 Buick 2-2 Bengal Roadster Concept,2000 Buick Regal GNX Show Car,2000 Buick Regal Cielo Concept,2000 Buick Regal,2000 Buick Park Avenue,2000 Buick LeSabre Limited,2000 Buick Century
Note:
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