VOLVO
ECM-P050462 - Brake Switch A / B Correlation. Algorithm Based Failures. Signal compare failure
System
Engine Control Module (ECM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
14 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), S60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V50 (2004–2013), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–), XC90 (2003–)
Show models by year and engine (39)
- Volvo C30 (2007–2013)2011–2013Engine D5204T, D5204T5 only
- Volvo C70 (2006–2013)2011Engine D5204T, D5204T5 only
- Volvo C70 (2006–2013)2012–2013All engines except: B5254T7
- Volvo S40 (2004–2013)2011–2012Engine D5204T, D5204T5 only
- Volvo S60 (2011–)2011–2012All engines except: B5254T5, D4162T
- Volvo S60 (2011–)2013All engines except: D4162T
- Volvo S60 (2011–)2014–2015All engines except: B4204T10, B4204T11, B4204T12, B4204T15, B4204T9, D4162T, D4204T5
- Volvo S80 (2007–)2007Engine B6324S, B8444S only
- Volvo S80 (2007–)2008Engine B6304T2, B6324S, B8444S only
- Volvo S80 (2007–)2009Engine B6304T2, B6324S, B8444S, D5244T10 only
- Volvo S80 (2007–)2010All engines except: B4204S3, B4204S4, B5254T10, B5254T11, B5254T8, D4164T, D4204T
- Volvo S80 (2007–)2011All engines except: B4204S3, B4204S4, B5254T10, B5254T11, B5254T8, D4164T
- Volvo S80 (2007–)2012All engines except: B5254T10, D4162T
- Volvo S80 (2007–)2013All engines except: D4162T
- Volvo S80 (2007–)2014–2015All engines except: B4204T11, B4204T12, B4204T15, D4162T, D4204T5
- Volvo V40 (2013–)2013–2014All engines except: D4162T, D5204T4, D5204T6
- Volvo V40 (2013–)2015All engines except: B4204T11, D4162T, D4204T14, D5204T6
- Volvo V40 Cross Country (2013–)2013–2014All engines except: D4162T, D5204T4, D5204T6
- Volvo V40 Cross Country (2013–)2015All engines except: B4204T11, D4162T, D4204T14, D5204T6
- Volvo V50 (2004–2013)2011–2012Engine D5204T, D5204T5 only
- Volvo V60 (2011–)2011–2013All engines except: D4162T
- Volvo V60 (2011–)2014–2015All engines except: B4204T11, B4204T12, B4204T15, B4204T9, D4162T, D4204T5
- Volvo V60 Cross Country (2015–)2015
- Volvo V70 (2008–)2008Engine B6304T2, B6324S only
- Volvo V70 (2008–)2009Engine B6304T2, B6324S, D5244T10 only
- Volvo V70 (2008–)2010All engines except: B4204S3, B4204S4, B5254T10, B5254T11, D4164T, D4204T
- Volvo V70 (2008–)2011All engines except: B4204S3, B4204S4, B5254T10, B5254T11, D4164T
- Volvo V70 (2008–)2012All engines except: B5254T10, D4162T
- Volvo V70 (2008–)2013All engines except: D4162T
- Volvo V70 (2008–)2014–2015All engines except: B4204T11, D4162T, D4204T5
- Volvo XC60 (2009–)2009Engine B6304T2 only
- Volvo XC60 (2009–)2010–2013
- Volvo XC60 (2009–)2014–2015All engines except: B4204T10, B4204T11, B4204T12, B4204T15, B4204T9, D4204T5
- Volvo XC70 (2008–)2008Engine B6324S only
- Volvo XC70 (2008–)2009Engine B6304T2, B6324S only
- Volvo XC70 (2008–)2010–2013
- Volvo XC70 (2008–)2014–2015All engines except: B4204T11, D4204T5
- Volvo XC90 (2003–)2007–2010Engine B6324S only
- Volvo XC90 (2003–)2011–2014Engine B6324S5 only
What does this fault code mean?
The ECM compares the brake light switch signal with the brake pedal switch position, which the brake control module (BCM) sends over the CAN network. The code is set when the signals show different brake pedal positions for a long time and on repeated occasions, or when no correct braking has taken place for a long time.
Possible causes
- Diagnose the cause in the brake control module (BCM)
- Diagnose the cause in the central electronic module (CEM)
- Contact resistance or oxidation in the connections to the brake light switch or brake position sensor
- Brake light switch incorrectly fitted or damaged
- Break or short to ground or supply voltage on the wiring to the brake pedal position sensor or the brake light switch
- Damaged brake pedal switch or brake position sensor
What you can do
- 1Read the codes in the brake control module (BCM) and the central electronic module (CEM) first, and repair them
- 2Check that the brake light switch is fitted correctly and that the brake pedal position sensor sits properly
- 3Check the connections to the brake light switch and brake pedal sensor for oxidation and chafed or broken wiring
- 4Check that the fuses are intact
- 5If you have a diagnostic tool, follow the brake pedal positions in live data and check that they agree when the pedal is pressed several times
- 6Do not work on the braking system yourself; have a workshop carry out the checks that need diagnostic equipment, and check after the repair that the fault does not return
Symptoms you may notice5
- Red warning symbol and message in the display
- Cruise control does not work at all
- Cruise control does not hold the set speed and disengages
- Autostart does not work
- The engine does not start, either sometimes or always
What the fault can affect3
- Autostart is blocked
- Cruise control is switched off while the fault is active, or for the drive cycle in which it was detected
- Automatic engine start/stop is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.