Code
B1265
ALFA ROMEO
B — Body
Cold air bypass flap control circuit
AI status
Completed
Completed
100%
Causes
- Open or short circuit in flap actuator wiring
- Corroded or loose connector at the actuator
- Faulty cold air bypass flap actuator (motor or potentiometer)
- Blown fuse or poor power supply to HVAC/actuator module
- Poor ground connection
- Mechanical obstruction or seized flap linkage
Symptoms
- HVAC cold air bypass flap does not move or responds intermittently
- Inability to achieve selected cabin temperature or incorrect air distribution
- Unusual clicking or motor noise from dash area
- Airflow feels wrong (too cold or warm) when settings changed
- DTC stored and HVAC warning or indicator may be present
What to check
- Scan vehicle and read stored DTCs including freeze frame and related HVAC codes
- Visually inspect wiring and connectors to the cold air bypass flap actuator for corrosion, damage or water ingress
- Check relevant fuses and relays for power to the HVAC/actuator circuit
- Attempt a commanded flap operation using a diagnostic scan tool and observe actuator behaviour
- Listen for actuator motor noise and try manual movement of the flap (with ignition off) to check for mechanical binding
- Back-probe actuator connector to verify supply voltage and ground while commanding the flap
Signal parameters
- Battery supply to actuator: ~11–14 V with ignition on (vehicle battery voltage)
- Control signal: PWM or switched control — varies between 0 V and battery voltage (or 0–5 V for low-voltage reference designs) when commanded
- Expected actuator resistance (motor/coils) typically low — usually a few ohms to a few hundred ohms depending on actuator type (consult vehicle-specific data)
- Open-circuit: infinite/OL on continuity check; short to ground: near 0 Ω to chassis
- Intermittent: voltage drops or erratic PWM duty when moving; use oscilloscope or scan-tool data to confirm
Diagnostic algorithm
- Connect a diagnostic scan tool and record DTCs, freeze frame and live data related to HVAC/flap position
- Attempt to actuate the cold air bypass flap from the scan tool while observing position feedback and listening for motor operation
- Perform a visual inspection of the actuator, linkage and surrounding components for physical damage or obstruction; free the mechanism if seized
- With ignition on, back-probe the actuator connector: verify battery positive supply, control signal behaviour when commanded, and good ground
- Check for continuity between actuator connector and the controlling module; repair any open or shorted wiring
- Inspect and test relevant fuses and relays; replace if defective
- If wiring and power/ground are good but actuator does not respond or position feedback is incorrect, bench-test or replace the actuator
- After repair or replacement, clear codes, re-run actuator tests and perform HVAC system calibration/relearn if required by manufacturer
- Road‑test / functional test HVAC to confirm proper flap operation and that the code does not return
Likely causes
- Failed flap actuator (most common)
- Damaged connector or pin corrosion at actuator
- Broken or chafed harness causing open/short
- Bad ground or missing power to actuator
- Flap stuck due to debris or broken linkage
Fault status
Status
Cold air bypass flap control circuit fault detected — electrical or mechanical issue preventing correct flap control.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Repair manuals
Manual library for ALFA ROMEO
89
Browse 89 ALFA ROMEO manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
ALFA ROMEO
-
ALFA ROMEO: 2024
-
ALFA ROMEO: 2023
-
Stelvio
-
ALFA ROMEO: 2022
-
Stelvio
-
ALFA ROMEO: 2021
-
Stelvio
-
ALFA ROMEO: 2020
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
B1265
FIAT
B — Body
Cold air bypass flap control circuit
AI status
Completed
Completed
100%
Causes
- Open or short circuit in flap actuator wiring
- Corroded or loose connector at the actuator
- Faulty cold air bypass flap actuator (motor or potentiometer)
- Blown fuse or poor power supply to HVAC/actuator module
- Poor ground connection
- Mechanical obstruction or seized flap linkage
Symptoms
- HVAC cold air bypass flap does not move or responds intermittently
- Inability to achieve selected cabin temperature or incorrect air distribution
- Unusual clicking or motor noise from dash area
- Airflow feels wrong (too cold or warm) when settings changed
- DTC stored and HVAC warning or indicator may be present
What to check
- Scan vehicle and read stored DTCs including freeze frame and related HVAC codes
- Visually inspect wiring and connectors to the cold air bypass flap actuator for corrosion, damage or water ingress
- Check relevant fuses and relays for power to the HVAC/actuator circuit
- Attempt a commanded flap operation using a diagnostic scan tool and observe actuator behaviour
- Listen for actuator motor noise and try manual movement of the flap (with ignition off) to check for mechanical binding
- Back-probe actuator connector to verify supply voltage and ground while commanding the flap
Signal parameters
- Battery supply to actuator: ~11–14 V with ignition on (vehicle battery voltage)
- Control signal: PWM or switched control — varies between 0 V and battery voltage (or 0–5 V for low-voltage reference designs) when commanded
- Expected actuator resistance (motor/coils) typically low — usually a few ohms to a few hundred ohms depending on actuator type (consult vehicle-specific data)
- Open-circuit: infinite/OL on continuity check; short to ground: near 0 Ω to chassis
- Intermittent: voltage drops or erratic PWM duty when moving; use oscilloscope or scan-tool data to confirm
Diagnostic algorithm
- Connect a diagnostic scan tool and record DTCs, freeze frame and live data related to HVAC/flap position
- Attempt to actuate the cold air bypass flap from the scan tool while observing position feedback and listening for motor operation
- Perform a visual inspection of the actuator, linkage and surrounding components for physical damage or obstruction; free the mechanism if seized
- With ignition on, back-probe the actuator connector: verify battery positive supply, control signal behaviour when commanded, and good ground
- Check for continuity between actuator connector and the controlling module; repair any open or shorted wiring
- Inspect and test relevant fuses and relays; replace if defective
- If wiring and power/ground are good but actuator does not respond or position feedback is incorrect, bench-test or replace the actuator
- After repair or replacement, clear codes, re-run actuator tests and perform HVAC system calibration/relearn if required by manufacturer
- Road‑test / functional test HVAC to confirm proper flap operation and that the code does not return
Likely causes
- Failed flap actuator (most common)
- Damaged connector or pin corrosion at actuator
- Broken or chafed harness causing open/short
- Bad ground or missing power to actuator
- Flap stuck due to debris or broken linkage
Fault status
Status
Cold air bypass flap control circuit fault detected — electrical or mechanical issue preventing correct flap control.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Repair manuals
Manual library for FIAT
26
Browse 26 FIAT manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
FIAT
-
FIAT: 2022
-
500X
-
-
FIAT: 2021
-
500X
-
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
B1265
Other
B — Body
Servo Motor Coolair Bypass Circuit Failure
AI status
Completed
Completed
100%
Causes
- Open or short circuit in flap actuator wiring
- Corroded or loose connector at the actuator
- Faulty cold air bypass flap actuator (motor or potentiometer)
- Blown fuse or poor power supply to HVAC/actuator module
- Poor ground connection
- Mechanical obstruction or seized flap linkage
Symptoms
- HVAC cold air bypass flap does not move or responds intermittently
- Inability to achieve selected cabin temperature or incorrect air distribution
- Unusual clicking or motor noise from dash area
- Airflow feels wrong (too cold or warm) when settings changed
- DTC stored and HVAC warning or indicator may be present
What to check
- Scan vehicle and read stored DTCs including freeze frame and related HVAC codes
- Visually inspect wiring and connectors to the cold air bypass flap actuator for corrosion, damage or water ingress
- Check relevant fuses and relays for power to the HVAC/actuator circuit
- Attempt a commanded flap operation using a diagnostic scan tool and observe actuator behaviour
- Listen for actuator motor noise and try manual movement of the flap (with ignition off) to check for mechanical binding
- Back-probe actuator connector to verify supply voltage and ground while commanding the flap
Signal parameters
- Battery supply to actuator: ~11–14 V with ignition on (vehicle battery voltage)
- Control signal: PWM or switched control — varies between 0 V and battery voltage (or 0–5 V for low-voltage reference designs) when commanded
- Expected actuator resistance (motor/coils) typically low — usually a few ohms to a few hundred ohms depending on actuator type (consult vehicle-specific data)
- Open-circuit: infinite/OL on continuity check; short to ground: near 0 Ω to chassis
- Intermittent: voltage drops or erratic PWM duty when moving; use oscilloscope or scan-tool data to confirm
Diagnostic algorithm
- Connect a diagnostic scan tool and record DTCs, freeze frame and live data related to HVAC/flap position
- Attempt to actuate the cold air bypass flap from the scan tool while observing position feedback and listening for motor operation
- Perform a visual inspection of the actuator, linkage and surrounding components for physical damage or obstruction; free the mechanism if seized
- With ignition on, back-probe the actuator connector: verify battery positive supply, control signal behaviour when commanded, and good ground
- Check for continuity between actuator connector and the controlling module; repair any open or shorted wiring
- Inspect and test relevant fuses and relays; replace if defective
- If wiring and power/ground are good but actuator does not respond or position feedback is incorrect, bench-test or replace the actuator
- After repair or replacement, clear codes, re-run actuator tests and perform HVAC system calibration/relearn if required by manufacturer
- Road‑test / functional test HVAC to confirm proper flap operation and that the code does not return
Likely causes
- Failed flap actuator (most common)
- Damaged connector or pin corrosion at actuator
- Broken or chafed harness causing open/short
- Bad ground or missing power to actuator
- Flap stuck due to debris or broken linkage
Fault status
Status
Cold air bypass flap control circuit fault detected — electrical or mechanical issue preventing correct flap control.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Repair manuals
Brands with available manuals
9,688
The library contains 9,688 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email