Description
OBD-II Trouble Code Description for P0121 Lexus
Throttle/Pedal Position Sensor/Switch “A” Circuit Range/Performance
What does this mean?
OBD2 Code P0121 Lexus 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 Lexus
Symptoms of a P0121 Lexus 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 Lexus
A code P0121 Lexus 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 Lexus:
2013 Lexus RX 450h F Sport,2013 Lexus RX 450h,2013 Lexus RX 350 F Sport,2013 Lexus RX 350,2013 Lexus LX 570,2013 Lexus LS EU-Version,2013 Lexus LS 600h L,2013 Lexus LS 460 F Sport,2013 Lexus LS 460,2013 Lexus LF-NX Concept,2013 Lexus GS 450h F Sport,2013 Lexus GS 450h,2013 Lexus GS 350 F Sport,2013 Lexus GS 350,2013 Lexus GS 250,2013 Lexus ES 300h,2013 Lexus ES350,2012 Lexus LF-LC Concept,2012 Lexus LF-CC Concept,2011 Lexus LFA,2011 Lexus LF-Gh Concept,2011 Lexus IS 350 F Sport,2011 Lexus IS 350,2011 Lexus CT 200h,2010 Lexus SC 430,2010 Lexus RX 450h,2010 Lexus RX 350,2010 Lexus LS 600h,2010 Lexus LS 460 Sport,2010 Lexus LS 460 L,2010 Lexus IS250C,2010 Lexus HS 250h,2010 Lexus GX 460,2010 Lexus GS 460,2010 Lexus GS 450h,2010 Lexus GS 350,2010 Lexus ES 350,2009 Lexus SC430,2009 Lexus LS,2009 Lexus LS460,2009 Lexus LF-Ch,2009 Lexus IS 350,2009 Lexus GX 470,2009 Lexus GS 460,2009 Lexus GS 450h,2009 Lexus GS 350,2008 Lexus LX 570,2008 Lexus LS 600h L,2007 Lexus LS,2007 Lexus LF,2006 Lexus SC,2006 Lexus IS350,2006 Lexus GS,2005 Lexus RX400h,2005 Lexus LFA Concept,2005 Lexus ES330,2004 Lexus RX330,2004 Lexus LS430
Note:
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