Test Point 29 - Auxiliary air pump relay
TEST POINT 29 - Auxiliary air pump relay - Fault code 1_44Possible Causes, Elimination, Remarks
The auxiliary air pump may be tested using the Actuator active menu item on the System Tester 9288.
Conditions for testing
Cylinder head temperature > 80°C (> 176°F).
After selecting "Actuator active", the auxiliary air pump will be activated after a waiting period of approx. 10 seconds.
This will be indicated by the " * " symbol shown in the upper right-hand corner of the display.
Activation of the pump is limited to 20 seconds.
When the pump is running, sensor voltage tends approaches 0 volts and oxygen sensor regulation approaches 1.20.
Activating the pump
If oxygen sensor regulation and sensor voltage do not change after the pump activating symbol has appeared on the display, check pump activation and the relay according to the wiring diagram.
Activating on-off valve
If the pump activating symbol is displayed, the pump is audibly running, but the oxygen sensor regulation does not approach 1.2 and the sensor voltage does not approach 0.1, the fault lies in the on-off valve area or its wiring.