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.

Fig. 1 Control Relay:

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

Test control relay by checking continuity between the following terminals of the control relay coil.



Confirm circuit tester polarity before checking continuity.
TERMINAL # CONTINUITY

3 - 5 Conductive (Approx 95 Ohms)
2 - 5 Conductive (Approx 95 Ohms)
6 - 7 Conductive (Approx 35 Ohms)
6 - 8 Conductive in one direction only

Control Reley Test Schematic:

Test the continuity of the control relay contacts between terminals 1 - 4 by connection a 12 volt power source to terminals 6 - 7 and testing for continuity at terminals 1 - 4.

RELAY CONDITION CONTINUITY

NOT ENERGIZED nonconductive (infinite Ohms)
ENERGIZED conductive (0 Ohms)

Test the continuity of the control relay contacts between terminals 2 - 4 by connecting a positive side 12 volt power source to terminal 8 and the negative side to terminal 6. Check for continuity at terminals 2 - 4.

RELAY CONDITION CONTINUITY

NOT ENERGIZED nonconductive (infinite Ohms)
ENERGIZED conductive (0 Ohms)

Relay Test:

Test the continuity of the control relay contacts between terminals 1 - 4 by connection a 12 volt power source to terminals 2 - 5 and testing for continuity at terminals 1 - 4.

RELAY CONDITION CONTINUITY

NOT ENERGIZED nonconductive (infinite Ohms)
ENERGIZED conductive (0 Ohms)

If the control relay fails any of the tests, it must be replaced.