Diagnostic trouble code (DTC) information EFI-621
WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
Condition
Diagnostic trouble code (DTC) EFI-621 (Fuel tank pressure sensor, signal) is stored if the engine control module (ECM) receives a signal from the tank pressure sensor corresponding to a pressure above +2.05 kPa (0.3 psi) (signal high) or below -3.10 kPa (-0.45 psi) (signal low).
Diagnostic trouble code (DTC) EFI-621 is stored if the signal is unstable (signal sporadic) for 25 seconds.
Substitute Value
- leakage diagnostic is disabled.
Possible Source
Signal too high:
- short-circuit to supply voltage in signal cable
- open-circuit in signal cable or ground lead
- contact resistance in terminals
- Defective fuel tank pressure sensor
Signal too low
- short-circuit to ground in signal cable
- open-circuit in power cable
- short-circuit to ground in air conditioning (A/C) pressure sensor
- short-circuit to ground in accelerometer power cable
- short-circuit to ground in power cable
- contact resistance in terminals
- defective fuel tank pressure sensor
- defective air conditioning (A/C) pressure sensor
- defective atmospheric pressure sensor
- defective accelerometer
Signal sporadic
- loose connections
- contact resistance in terminals
- defective air conditioning (A/C) pressure sensor
- defective accelerometer
- defective fuel tank pressure sensor
Fault symptom[s]
- none.