Lexus P0443 EVAP Canister Purge Valve Circuit Malfunction

Description

OBD-II Trouble Code Description for P0443 Lexus

Evaporative Emission System Purge Control Valve Circuit

What does this mean?

OBD2 Code P0443 Lexus definition:
The Evaporative Emissions System (EVAP) allows fumes from the gas tank to enter the engine to be burned, rather than vented into the atmosphere as an emission. The purge valve solenoid is supplied switched battery voltage. The ECM controls the valve by operating the ground circuit, opening the purge valve at specific times allowing these gasses to enter the engine. The ECM monitors the ground circuit as well, watching for faults. When the purge solenoid isn’t activated, the ECM should see a high voltage on the ground circuit. When the solenoid is activated, the ECM should see the ground voltage pulled low, close to zero. If the ECM doesn’t see these expected voltages, or senses an open in the circuit, this code is set.

Symptoms

Possible sumptoms of OBD code P0443 Lexus
P0443 Lexus trouble code symptoms could be just an malfunction indicator lamp (MIL) illumination. There may be no drivability problems at all. But, it’s also possible to have a lean condition or a rough running engine if the purge valve is stuck open. Usually though, these symptoms are accompanied by other EVAP codes. Another symptom may be excessive pressure in the gas tank in the form of a “whooshing” sound when the cap is removed, indicating a purge valve that isn’t working at all or stuck closed.

Causes

Possible causes of OBD code P0443 Lexus
To cause a P0443 Lexus, there has to be a problem with the purge control CIRCU LexusIT, not necessarily the valve. Usually they are a unit housing the valve and the solenoid as an assembly. Or it could be comprised of a separate solenoid with vacuum lines to a purge valve. That said, it could be any of the following: CIRCU LexusIT Bad purge solenoid (internal short or open) Wiring harness chafing or rubbing another component causing short or open on control circuit Connector worn, broken or shorted due to water intrusion Driver circuit inside powertrain control module (PCM) is bad

Possible Solutions

1. Using a scan tool, command the purge solenoid to activate. Listen or feel for a clicking coming from the purge solenoid. It should click once, or on some models it may click repeatedly. 2. If it doesn’t click with scan tool activation, unplug the connector and examing the solenoid and connector for damage, water, etc. Then check for battery voltage on the feed wire with the key on. If you have battery voltage, then ground the control side manually using a jumper wire and see if the valve clicks. If it does, then you know the solenoid is working properly but there is a problem with the control circuit. If it doesn’t click when you manually ground it, replace the purge solenoid. 3. To check for a problem on the control circuit (if the solenoid tests okay and you have voltage to the solenoid) plug the solenoid back in and remove the control circuit (ground) wire from the ECM connector (If you’re unsure how to do this, do not attempt). With the ground wire removed from the ECM, turn the key on and then manually ground the Purge valve control wire. The solenoid should click. If it does, then you know there is no problem with the control wire to the solenoid and there is a problem with the ECM purge solenoid driver circuit in the ECM. You’ll need a new ECM. However if it doesn’t click, then there must be an open in the wiring between the ECM and and the solenoid. You must find it and repair it.

Related Codes

P0440 Lexus P0441 Lexus P0442 Lexus P0446 Lexus P0453 Lexus P0455 Lexus P0456 Lexus


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

 

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