Code 22, Metering Valve Sensor (MVS)
Code 22 indicates ECM has read a high MVS voltage below a specified RPM, below a specified engine load, or for a time in excess of 10 seconds. Due to the pull-up resistor between terminals "C" and "R" within ECM, an open in MVS circuit will place about 5 volts (high MVS signal) at terminal "R" of ECM.
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- Checks circuit from MVS connector back to ECM terminal "C". Voltage should be above 4 volts because of pull-up resistor in ECM.CAUTION: A 10 Meg. ohm resistance ohmmeter must be used. A lower resistance voltmeter would read virtually zero.
- Checks to see if low voltage at MVS connector is an open in the circuit or faulty ECM. A normal reading at ECM is above 4 volts.
- This tests resistance of MVS itself. A normal reading is under 20,000 ohms.