Diagnostic Trouble Code (DTC) Information
Diagnostic trouble code (DTC) information
Condition
Diagnostic trouble code (DTC) ECM-4020 is stored if the control module receives a signal from the fuel tank pressure sensor which corresponds to a pressure higher than 20 h Pa (0.29 psi) (high signal) or lower than -30 hPa (-0.435 psi) (low signal) and interprets it as a fault. If the signal is higher than 10 hPa (0.145 psi) directly after start-up with an engine coolant temperature (ECT) lower than 35°C (95°F), the control module interprets it as a fault (faulty signal) and diagnostic trouble code (DTC) ECM-4020 is stored.
Substitute value
leakage diagnostic is disabled
Possible source
Signal too high:
- short-circuit to supply voltage in the signal cable
- open-circuit in the signal cable
- open-circuit in the ground lead.
- defective fuel tank pressure sensor
Signal too low:
- short-circuit to ground in the signal cable
- short-circuit to ground in power cable
- defective fuel tank pressure sensor
Faulty signal:
- contact resistance in terminals.
- defective fuel tank pressure sensor
Fault symptom[s]
- none