Checking the Fuel Injectors

Checking Injectors, Steps 1, 2, 3:

1 Connect an ISAT scan tool, contact the SF1 system, enter command code 3000-3003 and check by listening to the sound of each injector that they are all working (10 Hz, 10 seconds). If not, continue as described below.


2 Unplug the connector of the relevant injector and check the injector's resistance. Do this by taking a measurement directly across connecting pins 1 and 2 of the injector.


The correct resistance is 15-17 ohms (@20~C). If the resistance is different, fit a new injector.


If the resistance is OK, continue with the next point.

3 Turn the ignition switch to the Drive position and enter command code 3000-3003. Check that voltage pulses (10 Hz) (approx. 8 V DC) can be measured across pins 1 and 2 of the connector of the relevant injector.

If voltage is present, continue with point 6.


If there are no voltage pulses on any of the injector connections, continue as described below.


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 Injectors, Steps 4 & 5:

4 Check that battery positive voltage is present on pin 87 of the main relay when command code 3000-3003 is activated.

If it is not, check the main relay.


If voltage is present, check the wiring (unplug the connector for the IAC valve, where appropriate) between pin 1 of the valve connector and terminal 87 of the main relay for continuity/shorting to ground.


Remedy faulty wiring and connectors or continue with point 6.

5 With the ignition switched off, connect a break-out box to the ECM and wiring. Check the wiring for continuity/shorting to ground between pins 3, 4, 5 and 6 of the ECM and pin 1 of the relevant injector connector.

Remedy any faulty wiring or continue as described below.

6 Drive the car to check whether any fault symptoms persist. If so, ECM may be faulty. Review "Before Replacing ECM."