VOLVO
ECM-21FD - Long-term fuel trim, bank 2. Signal too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS80 (1999–2006), XC90 (2003–)
Show models by year and engine (2)
What does this fault code mean?
A collective code for fuel adaptation faults on bank 2. It is set when any underlying adaptation code is stored in two consecutive driving cycles, and it always comes together with one or more of them. Although the code is named for a signal that is too low, the underlying cause is what counts.
Possible causes
- Consequential fault from an underlying fault code for adaptive lambda regulation on bank 2
What you can do
- 1Start troubleshooting with the underlying bank 2 codes, since this code has no fault-tracing of its own
- 2Clear the code only after the root fault is fixed, then road test the car
- 3Have a diagnostic tool? Read the codes and note which bank 2 codes are stored next to this one
Symptoms you may notice1
- The check engine warning lamp comes on or behaves abnormally
General guidance for car owners. Diagnosis on the car can point to a different cause.