Checking the Fuel Pump Relay

Checking Fuel Pump Relay, Steps 1 , 2, 3:

1 Connect an ISAT scan tool, contact the SFI system and enter command code 3045.


Check that the relay is activated at a frequency of 1 Hz (for 10 seconds).


2 With the ignition switched off, connect a break-out box to the ECM wiring harness (ECM disconnected). Check operation of the relay as follows:


Turn the ignition switch to the Drive position and connect a jumper cable across terminals 56 and 24 of the break-out box. Check whether the relay is energized by measuring the voltage at fuse positions 14 and 28.


If the relay operates, continue with point 6.


If the relay operates but fastens in the energized condition, go to point 5.


If the relay does not operate, continue as described below.

3 Check whether battery positive voltage is present up to pins 86 and 30 of the relay.

NOTE:
When command code 30XX has been used, the car cannot be started for the following 12 minutes. Use command code FF00 to clear the function, following which the car can be started.

Checking Fuel Pump Relay, Steps 4 & 5:

4 If battery positive voltage is not present on terminals 86 and 30, check the supply cables from the + 15 and + 30 terminals for continuity/shorting to ground.


If the cables are OK, check whether the resistance across terminals 85 and 86 of the relay is about 60 ohms.


If it is not, replace the relay.

5 Check the resistance across terminals 30 and 87 and 87B of the relay. When the relay is not energized the resistance should be about 0 ohms and when energized less than 1 ohm.

If the relay is faulty, replace it.

6 If the fault persists in spite of the above checks, the ECM may be faulty. Review "Before Replacing ECM."