DTC 22

Fig. 022 - WIRING DIAGRAM for Code 22 Metering Valve Sensor (Signal Voltage High). VIN N, VIN T:

CODE 22

METERING VALVE SENSOR

(SIGNAL VOLTAGE HIGH)

4.3L VIN "T"

5.7 VIN "N"

Code 22 means that the ECM has seen a high MVS voltage:
a. Below a specified RPM.
b. Below a specified engine load.
c. For a time in excess of 10 seconds.
Due to the pull-up resistor between Terms. "C" and "R" within the ECM, an open in the MVS circuit will place about 5 volts (high MVS signal) at Term. "R" of the ECM.

Fig. 021 - Chart For Code 22 Metering Valve Sensor (Signal Voltage High).:

1. Checks the circuit from the MVS connector back to the ECM.Term."C". Voltage should read above 4V because of the pull-up resistor in the ECM. A 10 Meg. ohm or higher resistance meter must be used. A lower resistance voltmeter would read virtually zero.
2. Checks to see if the low voltage at the MVS connector is an open in the circuit or a faulty ECM. A normal reading at the ECM is above 4V.
3. This step tests the resistance of the MVS itself. A normal reading is under 20,000 ohms.