VOLVO
ECM-21CC - Long-term fuel trim, idling, bank 1. Upper 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?
At idle, the long-term fuel trim for bank 1 has nearly reached its upper limit, so the engine control module has to add extra fuel to keep the mixture right. The cause can be fuel with too high an ethanol content, an intake air leak or a damaged oxygen sensor.
Possible causes
- Too high an ethanol content in the fuel
- Intake air leakage
- Damaged oxygen sensor
What you can do
- 1Ask whether the car has recently been refuelled with a fuel other than usual, since too high an ethanol content can cause the code
- 2Check the intake system for air leaks, such as hoses and clamps at the intake manifold
- 3Have a workshop measure the ethanol content of the fuel, as this needs special equipment
- 4Have a diagnostic tool? Read the long-term fuel trim in live data at idle with the engine warm, and see whether it sits close to its upper position
- 5If nothing points to wrong fuel and the fault remains, have a workshop check the oxygen sensor and replace it 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.