DTC 621 - Fuel Tank Pressure Sensor Signal
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
- DTC 621 will set if ECM receives a signal from fuel tank pressure sensor that is greater than 2.95 kPa or less than -2.88 kPa. If signal is too low, check for short circuit to voltage in signal wire, open circuit in signal or ground wire, contact resistance in terminals, or defective fuel tank pressure sensor.
- If signal is too high, check for short circuit to ground in signal wire, open circuit in voltage supply wire, A/C pressure sensor voltage supply wire short circuited to ground, short circuit to ground in accelerometer voltage supply, contact resistance in terminals, or defective fuel tank pressure sensor.