VOLVO
ECM-21AD - Long-term fuel trim load, bank1. Lower limit
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2007Engine B5254T3 only
- Volvo C30 (2007–2013)2008–2013Engine B5254T7 only
- Volvo C70 (2006–2013)2006–2007Engine B5254T3 only
- Volvo C70 (2006–2013)2008–2013Engine B5254T7 only
- Volvo S40 (2004–2013)2005–2007Engine B5254T3 only
- Volvo S40 (2004–2013)2008Engine B5254T3, B5254T7 only
- Volvo S40 (2004–2013)2009–2012Engine B5254T7 only
- Volvo V50 (2004–2013)2005–2007Engine B5254T3 only
- Volvo V50 (2004–2013)2008–2012Engine B5254T7 only
What does this fault code mean?
Although the code is named for a lower limit, the condition is that the long-term correction of the fuel mixture has nearly reached its maximum at both lower and upper part load. The cause can be an intake leak, high fuel pressure, leaking injectors, the mass air flow sensor, the engine oil or a damaged oxygen sensor.
Possible causes
- Air leakage in the intake system
- High fuel pressure
- Leaking injectors
- Damaged mass air flow sensor
- Contaminated engine oil or oil level too high
- Damaged heated oxygen sensor
What you can do
- 1Check the intake system for air leakage
- 2Compare the oil level with the dipstick marks and look at the oil for contaminants
- 3Look for fuel leaks at the fuel lines and the injectors
- 4Have a diagnostic tool? Read the long-term fuel trim in live data during a test drive, and see whether it sits close to an extreme position
- 5If the fault remains, have a workshop measure the fuel pressure, check the injectors and replace the oxygen sensor if needed
Symptoms you may notice1
- The malfunction indicator lamp (MIL) comes on
General guidance for car owners. Diagnosis on the car can point to a different cause.