All values measured to ground unless otherwise noted
Conn./Plug/Pin Pin Information Test Value Comments
A37      
1.8 CAN Class B bus (high side). Mid speed data transfer bus input and output, exchanges data with other ECMs No reliable test. Check continuity of wiring. Approx. 5 VAC when data is on bus HHT is also used for
CAN diagnosis
1.9 CAN Class B bus (low side) See pin 1.8  
2.2 Circuit 30 fused power input 12 VDC at all times Feed from F4f4
2.3 Main ground to W7 Approx. 0 Ohms to ground  
2.4 Circuit 30 fused power input 12 VDC at all times Feed from F4f2
3.4 ATA tow sensor signal input > 2 VDC static value
Voltage varies when vehicle is moved
 
3.11 ATA/CL signal output 12 VDC when ATA/CL activated Internally linked to CAN, activated by S6/1s2 via N10/1
3.15 ATA tow sensor ground signal input No reliable test