Diesel (ALH)
Testing the EGR system is done in function 04 (Basic setting). This procedure activates the EGR valve every 10 seconds to make it possible to read the extreme values for EGR (Mass Air Flow Sensor) in display field 3.
- Connect scan tool and select control module for engine electronics with the "address word" 01. Engine must run at idle during this:
- Press buttons "0" and "4" for the function "initiate basic setting" and press "0" button to confirm input.
- Press buttons "0" "0" and "3" for the "Display group number 3" and press "0" to confirm input.
Display field 2 must switch between EGR active and EGR not active every 10 seconds.
Display field 3 and 4 must move in the following control range:
NOTE:
If a constant value of 550 mg/H is displayed in display field 3, check the mass air flow sensor. See appropriate service information.
EGR not active
- Specified value in display field 3: 400 to 580 mg/H
- Specified value in display field 4: 0 to 5%
EGR active
- Specified value in display field 3: 150 to 340 mg/H
- Specified value in display field 4: 95 to 100%
NOTE:
The readings in display field 3 are defendant on pressure and altitude. The displayed values refer to 0 m NN. If the measured values strongly differ due to altitude, check in display field 3 if there is a difference in specified value of at least 100 mg/H between the readings for EGR active and EGR not active.
If specifications are not obtained, see appropriate diagnostic information.