Testing Engine, Transmission, ABS, and SRS Systems
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Chapter 13
When you select an actuator test, the scan tool commands the ECM to activate the selected
actuator (Figure 13-12).
Figure 13-12 Sample actuator test initiated
Approximately 5 seconds later, the ECM deactivates the actuator (Figure 13-13).
Figure 13-13 Sample actuator test complete
All actuator tests except for injector tests must be performed with the key on and engine off
(KOEO). Select a KOEO test with the engine running and a screen like Figure 13-14 displays.
Figure 13-14 Sample key-on, engine-off (KOEO) test
Injector Tests (Engine Running Only)
Injector tests are available from the actuator test menu on most pre-OBD-II vehicles. These
tests are performed with the key on and engine running (KOER). The number of injector tests
available varies, a 4-cylinder MPI system has four tests; a six cylinder system has six.
When you select an injector test, the scan tool commands the ECM to disable the selected
injector (Figure 13-15).
Figure 13-15 Sample injector test initiated
About 5 seconds later, the ECM stops the test and re-enables the injector (Figure 13-16).
Figure 13-16 Sample injector test completed
ACTIVATING EGR SOLENOID VALVE
FOR 5 SECONDS.
EGR SOLENOID VALVE
TEST HAS BEEN COMPLETED.
PRESS Y TO REPEAT TEST.
PRESS N FOR ACTUATOR TEST MENU.
EGR SOLENOID VALVE
TEST HAS BEEN REJECTED.
PRESS Y TO REPEAT TEST.
PRESS NO FOR ACTUATOR TEST MENU.
DISABLING INJECTOR #1
FOR 5 SECONDS.
INJECTOR #1 (ENGINE RUNNING ONLY)
TEST HAS BEEN COMPLETED.
PRESS Y TO REPEAT TEST.
PRESS N FOR ACTUATOR TEST MENU.
