Have a early 2015, Non AVF 3500hd with factory DPN mirrors
the IPC and BCM updated to the newest calibrations.
My mirro although being early build has the ambient sensor in the mirror and front of truck. So front sensor is for hvac, radio temp info and the mirror sensor is for ecm/powertrain requirements.
Noticed my ecm is always reading -40 but the hmi temp is bang on.
Diagnosing mirror sensor originally Found no power and no ground at the sensor wires(definitely odd it had neither)
Front sensor like stated, 100%. Reference voltage and ground on the wiring.
acquired diagram and traced back to ecm and was going to test continuity in the wires but found my ecm connectors do not even have pins in the appropriate locations. (See diagram) connector x2 pin 24 and connector x3 pin 26 do not exist in my ecm harness.
Anyone come across this? Very interesting. CTS3 shows ambient at -40 and using mdi with GDS2 also shows under the ecm module as -40. So it’s definitely not using the front sensor but strange no wiring.
the IPC and BCM updated to the newest calibrations.
My mirro although being early build has the ambient sensor in the mirror and front of truck. So front sensor is for hvac, radio temp info and the mirror sensor is for ecm/powertrain requirements.
Noticed my ecm is always reading -40 but the hmi temp is bang on.
Diagnosing mirror sensor originally Found no power and no ground at the sensor wires(definitely odd it had neither)
Front sensor like stated, 100%. Reference voltage and ground on the wiring.
acquired diagram and traced back to ecm and was going to test continuity in the wires but found my ecm connectors do not even have pins in the appropriate locations. (See diagram) connector x2 pin 24 and connector x3 pin 26 do not exist in my ecm harness.
Anyone come across this? Very interesting. CTS3 shows ambient at -40 and using mdi with GDS2 also shows under the ecm module as -40. So it’s definitely not using the front sensor but strange no wiring.