The A/C Control Unit will only update the Ambient Temperature Display when vehicle speed is received from the ESC through the CAN lines.
DTC B1686 sets if the vehicle speed signal has not been received through the CAN lines.
Item
Detecting Condition
DTC Strategy
Check CAN signal
Faulty WSS.
CAN communication.
Enable Conditions
Ignition ON
Threshold value
No signal via CAN for 1.5 seconds or Error value received.
Failsafe
Substitued WSS = 0 MPH