System Tests

Fig. 1 Tachymetric relay by-pass harness:

1. Disconnect connector from the electronic control box.
2. Connect tachymetric relay by-pass harness 8.0141 P, Fig. 1, to fuel pump tachymetric relay and activate it.

Fig. 3 ECU connector pin # 8:

Fig. 35 ECU relay:

3. Check voltage between pin #8 of connector (8a), Fig. 3, and ground. Voltage reading should be 12 volts.
4. If reading = 0 volts, check connections and continuity of wire 148 and operation of the electronic control box relay (23), Fig. 35.

Fig. 4 ECU connector pin # 15:

Fig. 5 Frequency valve connector voltage test hookup:

5. Check voltage on the output side of the frequency valve. Test to be made at pin #15 of connector (8a), Fig. 4, wire 152A. If reading = 0 volts, check the frequency valve connector (3), Fig. 5, for current at pin (a).

Fig. 6 Frequency valve winding test:

6. If voltage at pin (a) wire 152 = 12 volts, check the windings of the frequency valve (3) using the test harness 8.0141 BH, Fig. 6. Resistance of the windings should be 2 to 3 ohms.
7. If voltage at pin (a) wire 152 = 0 volts check operation of the electronic control box relay (23), Fig. 35.

Fig. 7 ECU connector pins # 5, 16:

8. Check the connections between the electronic control box and vehicle ground. Test between pin #5 of the connector (8a) wire MS and vehicle ground, Fig. 7, resistance should be less than 1 ohm. Test between pin # 16 of the connector (8a) wire M16 and the vehicle ground, Fig. 7, resistance should be less than 1 ohm.