All values measured to ground unless otherwise noted
Conn./Plug/Pin Pin Information Test Value Comments
N70      
A.1 Main ground to W19 Approx. 0 Ohms to ground  
A.2 Circuit 30 main power input 12 VDC at all times Feed from F1f30
A.3 CAN Class B bus (low side). Mid speed data transfer bus input and output, exchanges data with other ECMs No reliable test. Check continuity to all appropriate ECMs. Approx. 5 VAC when data is on bus  
A.5 Driver-side outside rearview mirror dimming element voltage supply No reliable test Note 2
A.6 CAN Class B bus (high side) See pin A.3  
A.8 Driver-side outside rearview mirror dimming element voltage supply See pin A.5 Note 2
C.1 ???    
C.4 Circuit 15R power output 12 VDC with key in steering lock position "1"  
C.5 ???    
C.6 Backup mode recognition signal input Ignition on, shift lever in position "R" 12 VDC, all other positions 0 VDC  
C.8 Ground output Approx. 0 Ohms to ground  
N72      
1.1 Backup recognition signal input,
disables dimming function in backup mode
Ignition on, gear shift lever in position "R" 12VDC, mirror surface becomes brighter  
1.3 CAN Class B bus (low side). Mid speed data transfer bus input and output, exchanges data with other ECMs No reliable test. Check continuity to all appropriate ECMs. Approx. 5 VAC when data is on bus  
1.4 CAN Class B bus (high side) See pin A.3  
1.5 Circuit 30 main power input 12 VDC at all times Feed from F1f7
1.6 Main ground to W18 Approx. 0 Ohms to ground  
Note 1 Due to various functions N70 and N72 are split up in several system diagrams, therefore only the relating pins are listed. Pins not shown are unrelated to this system    
Note 2 Dimming functional test Cover daylight sensor of interior mirror, mirror surface of interior and driver-side outside mirrors become dark with flashlight shining towards interior mirror