VOLVO
ECM-3503 - Misfire, at least one cylinder
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?
The engine misfires to a degree that risks damaging the catalytic converter, and the control module has registered it. This code is always set together with a code showing which cylinder misfires, so both should be read.
Possible causes
- Temporary fuel stoppage
- Repeated cold starts where the engine does not reach operating temperature between starts
- Contaminated or incorrect fuel
- Air leakage
- Blocked or leaking injectors
- Incorrect fuel pressure
What you can do
- 1Read both fault codes, since this code always comes with a code for the misfiring cylinder
- 2Check that there is fuel in the tank and that the engine oil level is correct
- 3Check that the intake does not leak air and that the crankcase ventilation is not blocked
- 4If you have a diagnostic tool: check in live data which cylinder has the most misfires
- 5Have a workshop measure fuel pressure and compression and check the injectors with diagnostic equipment
Symptoms you may notice5
- The engine misfires
- The engine is difficult to start
- Deterioration in performance
- Uneven idle
- Some cylinders are not firing properly
What the fault can affect3
- Catalytic converter diagnosis is switched off
- Leakage diagnosis is switched off
- Rear oxygen sensor control is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.