Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2012 Fiat 500c LoungeFACTORY OEM SERVICE PROCEDURE
DTC Index: HVAC
DIAGNOSTIC CODE INDEX
| DTC | Description |
|---|---|
| B1901-11 | FRONT MODE DOOR 1 SENSOR CONTROL - CIRCUIT SHORT TO GROUND |
| B1901-15 | FRONT MODE DOOR 1 SENSOR CONTROL - CIRCUIT SHORT TO BATTERY OR OPEN |
| B1902-11 | FRONT MODE DOOR 1 ACTUATOR CONTROL - CIRCUIT SHORT TO GROUND |
| B1902-12 | FRONT MODE DOOR 1 ACTUATOR CONTROL - CIRCUIT SHORT TO BATTERY |
| B1902-77 | FRONT MODE DOOR 1 CONTROL - COMMANDED POSITION NOT REACHABLE |
| B1905-11 | MAIN/LEFT TEMPERATURE DOOR 1 SENSOR CONTROL - CIRCUIT SHORT TO GROUND |
| B1905-15 | MAIN/LEFT TEMPERATURE DOOR 1 SENSOR CONTROL - CIRCUIT SHORT TO BATTERY OR OPEN |
| B1906-11 | MAIN/LEFT TEMPERATURE DOOR 1 ACTUATOR CONTROL - CIRCUIT SHORT TO GROUND |
| B1906-12 | MAIN/LEFT TEMPERATURE DOOR 1 ACTUATOR CONTROL - CIRCUIT SHORT TO BATTERY |
| B1906-77 | MAIN/LEFT TEMPERATURE DOOR 1 - COMMANDED POSITION NOT REACHABLE |
| B1909-11 | RECIRCULATION DOOR CONTROL - CIRCUIT SHORT TO GROUND |
| B1909-12 | RECIRCULATION DOOR CONTROL - CIRCUIT SHORT TO BATTERY |
| B1909-77 | RECIRCULATION DOOR - COMMANDED POSITION NOT REACHABLE |
| B1914-11 | PANEL DUCT TEMPERATURE SENSOR - CIRCUIT SHORT TO GROUND |
| B1914-15 | PANEL DUCT TEMPERATURE SENSOR - CIRCUIT SHORT TO BATTERY OR OPEN |
| B1915-11 | FLOOR DUCT TEMPERATURE SENSOR - CIRCUIT SHORT TO GROUND |
| B1915-15 | FLOOR DUCT TEMPERATURE SENSOR - CIRCUIT SHORT TO BATTERY OR OPEN |
| B1916-11 | EVAPORATOR TEMPERATURE SENSOR - CIRCUIT SHORT TO GROUND |
| B1916-15 | EVAPORATOR TEMPERATURE SENSOR - CIRCUIT SHORT TO BATTERY OR OPEN |
| B1917-11 | CABIN TEMPERATURE SENSOR - CIRCUIT SHORT TO GROUND |
| B1917-15 | CABIN TEMPERATURE SENSOR - CIRCUIT SHORT TO BATTERY OR OPEN |
| B1918-49 | CABIN TEMPERATURE SENSOR MICRO FAN - INTERNAL ELECTRONIC FAILURE |
| B1919-16 | BLOWER MOTOR CONTROL - CIRCUIT VOLTAGE BELOW THRESHOLD |
| B1919-17 | BLOWER MOTOR CONTROL - CIRCUIT VOLTAGE ABOVE THRESHOLD |
| B1923-42 | GENERAL MEMORY FAILURE |
| B1924-49 | CONTROL HEAD - INTERNAL ELECTRONIC FAILURE |
| B1926-11 | MODE/TEMPERATURE DOOR VOLTAGE REFERENCE - CIRCUIT SHORT TO GROUND |
| B1926-12 | MODE/TEMPERATURE DOOR VOLTAGE REFERENCE - CIRCUIT SHORT TO BATTERY |
| U0019-87 | CAN B BUS - NO SIGNAL |
| U0019-88 | CAN B BUS OFF |
| U1700-86 | IMPLAUSIBLE DATA RECEIVED FROM BCM |
| U1700-87 | LOST COMMUNICATION WITH BCM |
| U1701-86 | IMPLAUSIBLE DATA RECEIVED FROM PCM |
| U1701-87 | LOST COMMUNICATION WITH PCM |
| U1703-86 | IMPLAUSIBLE DATA RECEIVED FROM IPC |
| U1703-87 | LOST COMMUNICATION WITH IPC |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.