1.1.3.3. Measurements with multimeter on CAN network
Test 1.1.3.3.1: Voltage supply of engine compartment CAN control modules
Test 1.1.3.3.2: Resistance test of engine compartment CAN
1.1.3.3.1. Voltage supply of engine compartment CAN control modules
Test 1.1.3.3.1.1: Check power supply at control unit A1 (Instrument cluster).
Test 1.1.3.3.1.2: Check power supply at control unit A89 (DTR controller unit).
Test 1.1.3.3.1.3: Check power supply at control unit N3/10 (ME-SFI [ME] control unit).
Test 1.1.3.3.1.4: Check power supply at control unit N15/3 (ETC [EGS] control unit).
Test 1.1.3.3.1.5: Check power supply at control unit N15/5 (Electronic selector lever module control unit).
Test 1.1.3.3.1.6: Check power supply at control unit N15/6 (Sprintshift control module).
Test 1.1.3.3.1.7: Check power supply at control unit N47-5 (ESP, SPS [PML] and BAS control unit).
Test 1.1.3.3.1.8: Check power supply at control unit N51 (AIRmatic with ADS control module).
Test 1.1.3.3.1.9: Check power supply at control unit N63/1 (DTR control module).
Test 1.1.3.3.1.10: Check power supply at control unit N71 (Headlamp range adjustment control module).
Test 1.1.3.3.1.11: Check power supply at control unit N73 (EIS [EZS] control unit).
Test 1.1.3.3.1.12: Check power supply at control unit N80 (Steering column module).
Test 1.1.3.3.1.13: Check power supply at control unit Y3/8n4 (Fully integrated transmission control (VGS) control unit).
1.1.3.3.1.1. Check power supply at control unit A1 (Instrument cluster).
Test prerequisites
- The fuses are OK.
- The power supply of the control unit N10/1 (Front SAM control unit with fuse and relay module) is OK.
Test sequence
- Switch off ignition.
- Detach the socket at component A1 (Instrument cluster).
- Measure direct voltage with multimeter between sockets (A1) 1 and (A1) 6
- Measure direct voltage with multimeter between sockets (A1) 2 and (A1) 6
- Measure direct voltage with multimeter between sockets (A1) 3 and (A1) 6
- Switch on ignition.
Specified value
- Voltage [11.0...14.5] V
Question:Is the measurement value OK?
YES
The measurement value is OK.Possible cause and remedy
- Perform inspection of connector and of socket for bent pins and enlarged contacts.
- Control unit A1 (Instrument cluster)
End of test
NO
The measurement value is not OK.Possible cause and remedy
- Line between component A1 (Instrument cluster) and component N10/1 (Front SAM control unit with fuse and relay module)
- Lines between A1 (Instrument cluster) and W28/1 (Ground, left inner door sill)
- Perform inspection of connector and of socket for bent pins and enlarged contacts.
End of test
1.1.3.3.1.2. Check power supply at control unit A89 (DTR controller unit).
Check power supply at control unit A89 (DTR controller unit).
