Control Relay

System Schematic:

Failure of the control relay could interrupt power supply to the fuel pump, injectors and ECU, resulting in start failure. Also see Fuel Pump and/or Power Circuits in TESTING PROCEDURES.


Caution
Use caution when connecting jumper wires to the relay. If they are incorrectly connected the relay will be damaged.

Confirm circuit tester polarity before checking continuity.

Control Relay:

Test control relay by removing relay and checking the following terminals of the control relay In the following order.

Fig. 1 Relay Test:

1. Connect jumper wires between relay terminals 10 and 8 and a 12v power source. Terminal 10 is positive (+) and 8 is negative (-).

2. Measure the voltage at terminals 4 and 5 with the power connected and disconnected at terminal 8.

POWER TO RELAY VOLTAGE READING TERMINALS 4 & 5

On System Voltage
Off 0 Volts

Fig. 2 Relay Test:

3. Connect jumper wires between relay terminals 9 and 6 and a 12v power source. Terminal 9 is positive (+) and 6 is negative (-).

4. Check for continuity at terminals 2 and 3 with the power connected and disconnected at terminal 6.

POWER TO RELAY CONTINUITY READING TERMINALS 2 & 3

On Continuity
Off No Continuity

Fig. 3 Relay Test:

5. Connect jumper wires between relay terminals 3 and 7 and a 12v power source. Terminal 3 is positive (+) and 7 is negative (-).

6. Measure the voltage at terminal 2 with the power connected and disconnected at terminal 7.

POWER TO RELAY VOLTAGE READING TERMINAL 2

On System Voltage
Off 0 Volts

7. Replace the control relay if it fails any of the previous tests.