F8:ecu Control Inj. Control Opel Frontera A

Motronic M 1.5.4 Quick Check F8:ECU CONTROL

INJ. CONTROL

Affected Terminals: 16, 17, 34, 35

Possible Trouble Codes: 25, 26, 27, 28, 81, 82, 83, 84

Engine running at idle speed

Engine throttle valve CLOSED (accelerator pedal in idle position)

Vehicle stationary

Switch off all consumers

AC switched OFF

Press key F8 in the system main menu, select the desired test using the arrow keys and confirm with YES. Follow the instructions in the diagnostic tester display.

Note:

In this test mode, the diagnostic tester sets the firing angle in the control unit to a fixed value and the idle speed adjuster to a fixed position. There is no longer any regulation of the firing angle and idle speed adjuster. It is then possible to switch off the injectors for the various cylinders.

After the YES key is pressed in the display on the right, diagnostic tester uses the control unit to stabilise the engine speed at approx. 1200 rpm. After stabilisation in the above range, the idle speed adjuster position is no longer altered and at this point the actual test can begin. During the stabilisation phase, the display on the right can be seen.

If the engine is not properly warm (coolant temperature lower than 100 °C/212 °F) when this test is performed the engine speed may oscillate considerably between approx. 1300 and 2000 rpm in the upper engine speed range (approx. 1900 rpm). To prevent this, always perform this test at high engine temperatures.

After the stabilisation phase, it is possible to select each cylinder using the arrow key UP and then with the arrow key DOWN to switch off the injector of the selected cylinder for 3 s.

In addition, the YES and NO keys can be used to display the various data list parameters. Key F9 is used to store the data as in the snapshot mode.

After fixing the firing angle and the idle speed adjuster position, i.e. after the actual start of the test and before deactivating an injector, the engine runs at approx. 1200 rpm. The oxygen sensor control functions normally. The test should only be started if the cooling fan is not running (otherwise the engine speed may be approx. 200 rpm lower).

: SELECT INJ.

: OFF (3 SECS)

(YES)

Once an injector is deactivated, the engine speed sinks by approx. 200 rpm. If the cooling fan starts running during the deactivation phase, this may lead to a further decrease of the engine speed of approx. 200 rpm. In this test phase, uncombusted oxygen from the deactivated cylinder gains access to the exhaust pipe. This means that the engine runs lean and therefore that the oxygen sensor constantly displays a voltage lower than 100 mV. The integrator, on the other hand, operates at a correspondingly higher rate (greater than 128 steps), as the system attempts to enrich the mixture.

The above described check should be performed consecutively for each cylinder. They should all indicate the same response, i.e. the engine speed should sink by the same amount for each cylinder The purpose of this check is not to test the function of the injectors, but is intended as a check of the mechanism/tightness/compression of each individual cylinder.