Frequency Valve: Testing and Inspection

Fig. 20 ECU connector pin # 15:

Fig. 21 Frequency valve connector:

1. Connect a voltmeter between pin 15, Fig. 20, of connector and the vehicle ground. Voltage reading should be above 12 volts.
2. If incorrect, connect a voltmeter between terminal (1) of frequency valve (M838) connector (wire 152), Fig. 21, and vehicle ground. Voltage reading should be above 12 volts.

Fig. 19 ECU relay:

Fig. 6 Frequency valve winding test:

3. If incorrect, check the operation of the ECU relay (M748), Fig. 19, and the electrical circuit continuity.
4. If correct, connect an ohmmeter between frequency valve (M838), Fig. 6, terminals. For this check use harness (-).0141BH. Resistance should be between 2 and 3 ohms.
5. If incorrect replace the frequency valve.
6. If correct, check the electrical continuity between the frequency valve and the ECU connector (wire 152A).