Description
OBD-II Trouble Code Description for P0231 Mercedes
Fuel Pump Secondary Circuit Low
What does this mean?
OBD2 Code P0231 Mercedes definition:
The fuel pump is powered by the fuel pump relay. When the PCM (powertrain control module) activates the fuel pump relay, voltage is supplied to the fuel pump and it pressurizes the fuel system. Some vehicles have a feedback on the fuel pump supply circuit. This is simply a circuit spliced into the voltage feed to the fuel pump. The splice is usually located close to the PCM. The PCM monitors this feedback circuit to ensure that there is proper voltage being sent to the fuel pump. As it activates the fuel pump relay, it expects to see battery voltage on the feedback circuit. If it sees voltage that is too low or no voltage at all, it may set P0231 Mercedes.
Symptoms
Possible sumptoms of OBD code P0231 Mercedes
Symptoms of a P0231 Mercedes DTC may include: No start Start and stall Misfire Inadequate fuel supply
Causes
Possible causes of OBD code P0231 Mercedes
Potential causes of a P0231 Mercedes code include: Bad FP (fuel pump) relay Harness chafing causing open in fuel pump supply circuit Loose/damaged connectors Open in feedback circuit Fuel pump fuse blown due to short to ground NOTE: If no drivability complaints are present and P0231 Mercedes code is stored, suspect open in feedback circuit between splice and PCM
Possible Solutions
To diagnose fuel pump circuits there’s no replacement for a good wiring diagram. Try to locate one before attempting a complex repair. If the vehicle will start and run and no drivability complaints are present, then suspect an open in the feedback circuit between the PCM and where it splices into the fuel pump supply voltage circuit. Repair as necessary. If the vehicle doesn’t start or starts and dies due to low fuel pressure, check the fuel pump fuse. If it’s blown check for a short to ground on the fuel pump voltage supply circuit. Do this by removing the FP relay and then check the resistance between the voltage supply circuit at the fuel pump connector and ground. If you have little resistance indicating a short to ground, unplug the fuel pump and check again. If it shows high or infinite resistance after unplugging the fuel pump, replace the shorted fuel pump. If the resistance is still low after unplugging the fuel pump then repair short in the FP voltage supply circuit If the resistance check is showing that the fuel pump supply circuit is okay then re-check between the FP fuse and the FP relay. There has to be a short somewhere. Check for wiring harness chafing in certain areas. Repair as necessary. If the fuel pump fuse isn’t blown and the vehicle won’t start or starts and stalls due to low fuel pressure then remove the fuse and check that voltage is present to the fuse. Then check that voltage is traveling from the fuse to the FP relay by re-installing the FP fuse and checking for battery voltage at the FP relay. If the FP fuse or the FP relay doesn’t have voltage supplied to it, the fuel pump will not operate. Find the open in the circuit and repair as necessary. If both the FP fuse and the FP relay have sufficient voltage, remove the FP relay and install a fused jumper wire to complete the FP voltage supply circuit (Usually you do this by jumping terminals 30 & 87 in most relays-check a wiring diagram to be sure). If the fuel pump runs, replace the faulty FP relay and recheck. If the fuel pump doesn’t run check for voltage present (with jumper connected or by cycling the ignition key with FP relay installed) at the fuel pump connector at the fuel tank. If voltage is present verify that the ground circuit is intact. If both are okay, replace the fuel pump. If voltage isn’t present at the fuel pump with fused jumper wire installed, repair open in fuel pump voltage supply circuit.
The OBD2 Code Information Be Applicable For Mercedes-Benz:
2013 Mercedes-Benz SLS AMG GT,2013 Mercedes-Benz SL65 AMG,2013 Mercedes-Benz SL550,2013 Mercedes-Benz SL500,2013 Mercedes-Benz SL-Class,2013 Mercedes-Benz GLK350 4Matic,2013 Mercedes-Benz GLK-Class,2013 Mercedes-Benz GL63 AMG,2013 Mercedes-Benz GL-Class,2013 Mercedes-Benz G63 AMG 6×6 Concept,2013 Mercedes-Benz G63 AMG,2013 Mercedes-Benz G550,2013 Mercedes-Benz G350 Bluetec,2013 Mercedes-Benz G-Class,2013 Mercedes-Benz E300 BlueTEC Hybrid,2013 Mercedes-Benz Citan,2013 Mercedes-Benz CLS Shooting Brake,2013 Mercedes-Benz A-Class AMG Sport,2013 Mercedes-Benz A-Class,2012 Mercedes-Benz SLS AMG Roadster,2012 Mercedes-Benz SLK55 AMG,2012 Mercedes-Benz SLK350,2012 Mercedes-Benz SLK250 CDI,2012 Mercedes-Benz SLK-Class,2012 Mercedes-Benz ML63 AMG,2012 Mercedes-Benz M-Class,2012 Mercedes-Benz E63 AMG Wagon,2012 Mercedes-Benz E63 AMG,2012 Mercedes-Benz CLS63 AMG,2012 Mercedes-Benz CLS550,2012 Mercedes-Benz CLS350 CDI,2012 Mercedes-Benz CLS-Class,2012 Mercedes-Benz C63 AMG,2012 Mercedes-Benz C-Class,2012 Mercedes-Benz B-Class,2011 Mercedes-Benz Vito,2011 Mercedes-Benz Viano,2011 Mercedes-Benz SLS AMG,2011 Mercedes-Benz S63 AMG,2011 Mercedes-Benz S600 Pullman Guard,2011 Mercedes-Benz R-Class,2011 Mercedes-Benz ML 63 AMG,2011 Mercedes-Benz G-Class,2011 Mercedes-Benz F125 Concept,2011 Mercedes-Benz E550 Cabriolet,2011 Mercedes-Benz E350 Cabriolet,2011 Mercedes-Benz E350 4Matic Wagon,2011 Mercedes-Benz E-Class L,2011 Mercedes-Benz E-Class Cabriolet,2011 Mercedes-Benz CL65 AMG,2011 Mercedes-Benz CL63 AMG,2011 Mercedes-Benz CL500,2011 Mercedes-Benz CL-Class,2011 Mercedes-Benz C-Class DR 520,2011 Mercedes-Benz B55 Concept,2011 Mercedes-Benz A-Class E-CELL,2011 Mercedes-Benz A-Class Concept,2010 Mercedes-Benz S65 AMG,2010 Mercedes-Benz S63 AMG,2010 Mercedes-Benz S400 BlueHYBRID,2010 Mercedes-Benz S-Class,2010 Mercedes-Benz ML450 Hybrid,2010 Mercedes-Benz GLK-Class,2010 Mercedes-Benz GL550,2010 Mercedes-Benz E63 AMG Estate,2010 Mercedes-Benz E63 AMG,2010 Mercedes-Benz E550 Coupe,2010 Mercedes-Benz E550,2010 Mercedes-Benz E350 Coupe,2010 Mercedes-Benz E350,2010 Mercedes-Benz E-Class,2010 Mercedes-Benz Biome Concept,2010 Mercedes-Benz B-Class F-Cell,2009 Mercedes-Benz SL65 AMG,2009 Mercedes-Benz SL63 AMG,2009 Mercedes-Benz SL-Class,2009 Mercedes-Benz ML 63 AMG,2009 Mercedes-Benz M-Class,2009 Mercedes-Benz G55 AMG,2009 Mercedes-Benz G-Class,2009 Mercedes-Benz CLS 63 AMG,2009 Mercedes-Benz CLS 280,2009 Mercedes-Benz CLC,2009 Mercedes-Benz B-Class,2009 Mercedes-Benz A-Class,2008 Mercedes-Benz SL,2008 Mercedes-Benz SLR,2008 Mercedes-Benz R-Class,2008 Mercedes-Benz CL65 AMG,2008 Mercedes-Benz C63 AMG,2008 Mercedes-Benz C-Class,2007 Mercedes-Benz S 63 AMG,2007 Mercedes-Benz S 600 Guard,2007 Mercedes-Benz S 500 4MATIC,2007 Mercedes-Benz S65 AMG,2007 Mercedes-Benz S550,2007 Mercedes-Benz R 63 AMG,2007 Mercedes-Benz G-Class,2007 Mercedes-Benz CL 63 AMG,2007 Mercedes-Benz CL 600,2007 Mercedes-Benz CL 500,2007 Mercedes-Benz CLS 63 AMG,2007 Mercedes-Benz CLS 350 CGI,2006 Mercedes-Benz SL 65 AMG,2006 Mercedes-Benz SL 600,2006 Mercedes-Benz SL 55 AMG,2006 Mercedes-Benz SL 500,2006 Mercedes-Benz SL 350,2006 Mercedes-Benz SLK 55 AMG SS,2006 Mercedes-Benz SL-Class,2006 Mercedes-Benz S-Class,2006 Mercedes-Benz R500,2006 Mercedes-Benz ML 63 AMG,2006 Mercedes-Benz ML500,2006 Mercedes-Benz ML350,2006 Mercedes-Benz GL 420 CDI,2006 Mercedes-Benz GL450,2006 Mercedes-Benz GL-Class,2006 Mercedes-Benz E 63 AMG,2006 Mercedes-Benz E-Class,2006 Mercedes-Benz CLK 63 AMG,2006 Mercedes-Benz B200 CDI,2006 Mercedes-Benz B150,2005 Mercedes-Benz SLK350,2005 Mercedes-Benz CLS500,2005 Mercedes-Benz CLK350,2005 Mercedes-Benz AClass
Note:
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