ECM-4020 - Fuel tank pressure sensor. Faulty signal. Intermittent fault
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:
9 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008), V70 XC (1998–2000), V70 XC / XC70 (2001–2007)
Show models by year and engine (16)
- Volvo C70 Cabriolet (1998–2005)1999, 2001–2002
- Volvo C70 Cabriolet (1998–2005)2000All engines except: B5244S
- Volvo C70 Coupé (1998–2002)1999All engines except: B5254S DENSO
- Volvo C70 Coupé (1998–2002)2000All engines except: B5244S
- Volvo C70 Coupé (1998–2002)2001–2002
- Volvo S60 (2001–2009)2001All engines except: B5244S, B5244S2, D5244T
- Volvo S70 (1997–2000)1999Engine B5204T3, B5204T4, B5234T3, B5234T7, B5254T only
- Volvo S70 (1997–2000)2000Engine B5204T3, B5204T4, B5234T3, B5234T7, B5244T only
- Volvo S80 (1999–2006)1999–2000All engines except: B5244S, B5244S2, D5252T MSA 15.8
- Volvo S80 (1999–2006)2001Engine B5204T5, B5234T7, B5244T3, B6284T, B6294S only
- Volvo V70 (1997–2000)1999Engine B5204T3, B5204T4, B5234T3, B5234T7, B5234T8, B5254T only
- Volvo V70 (1997–2000)2000All engines except: B5244S, B5244S2, B5244SG, B5244SG2, D5252T MSA 15.8
- Volvo V70 (2000–2008)2000All engines except: D5252T MSA 15.8
- Volvo V70 (2000–2008)2001Engine B5204T5, B5234T3, B5234T7, B5244T3 only
- Volvo V70 XC (1998–2000)1999–2000
- Volvo V70 XC / XC70 (2001–2007)2001
What does this fault code mean?
At some point the engine control module received a signal from the fuel tank pressure sensor that did not make sense. The fault is stored as intermittent, meaning it comes and goes and may not be present right now. The sensor measures pressure in the fuel tank, and the leak diagnosis depends on a correct signal. The fault can be in the sensor, the wiring or the connectors.
Possible causes
- Signal wire short-circuited to voltage, or open-circuited
- Open circuit in the ground wire
- Signal wire short-circuited to ground
- Supply wire short-circuited to ground
- Defective fuel tank pressure sensor
- Contact resistance in the connections
What you can do
- 1Read and note the fault code, clear it and test drive the car to see if it returns
- 2Check that the connector at the fuel tank pressure sensor is firmly seated and free from oxidation and corrosion
- 3Look for chafed or pinched wiring to the fuel tank pressure sensor, especially where the harness can move
- 4Use a multimeter to check that the signal wire has no contact with ground or positive and is not open-circuited
- 5Have you got a diagnostic tool: follow fuel tank pressure in live data with the ignition on and check that the value changes smoothly without jumping
- 6Have a workshop with diagnostic equipment check the fuel tank pressure sensor if the fault comes back
Symptoms you may notice1
- No noticeable symptoms for the driver
What the fault can affect1
- The fuel system leak diagnosis is disabled
General guidance for car owners. Diagnosis on the car can point to a different cause.