Code
B1744
MITSUBISHI
B — Body
Hazard button fail
Views:
UK: 6
EN: 5
RU: 4
AI status
Completed
Completed
100%
Causes
- Faulty hazard (emergency flasher) switch or internal contacts
- Open, shorted or intermittent wiring between switch and Body/BCM
- Corroded or loose connector at switch or body control module
- Blown fuse or faulty flasher/relay (if used separately)
- Water intrusion or contamination in the switch assembly
- Body/BCM (body control module) input circuit or internal failure
Symptoms
- Hazard/emergency flashers will not operate when switch is pressed
- Hazard indicator lamp on the instrument cluster does not illuminate or flash
- Turn signals may still operate normally (depending on vehicle wiring)
- DTC B1744 stored and warning lamp or message present on scan tool
- Intermittent operation of hazard lights (works sometimes, fails other times)
What to check
- Use a scan tool to read/record freeze frame and live data for the hazard switch and related BCM inputs
- Visually inspect the hazard switch for physical damage, contamination or fluid ingress
- Inspect related fuses and relays for continuity and correct rating
- Check switch connector for bent pins, corrosion or looseness; wiggle test while observing live data
- Measure battery voltage at the switch supply pin with ignition on (should be ~12 V)
- Perform continuity test between switch output and BCM input; check for shorts to ground or battery
Signal parameters
- Switch supply voltage: ~12 V (battery/ignition supply) with key ON
- Switch output: contact closure to ground or to a BCM input (voltage changes when pressed)
- Continuity/resistance across switch contacts: near 0 ohms when pressed, high/OL when released (spec dependent)
- Flasher control: pulsed output from BCM or flasher relay (check for pulsed 12 V to lamp circuit when activated)
- CAN/LIN: hazard switch status may be transmitted as a message/bit on the vehicle network (verify with a capable scan tool)
Diagnostic algorithm
- Read and record DTC(s) and live data with a diagnostic scan tool. Note whether the hazard switch status is reported and how it behaves when pressed.
- Visually inspect the switch and surrounding trim for damage or contamination. Check harness and connector for corrosion, broken pins, or water ingress.
- Check related fuses and relays for continuity. Replace any blown fuse with correct rating before further testing.
- With ignition ON, back-probe the switch connector: verify supply voltage (≈12 V) and that the switch output changes state when pressed. If no supply, trace to fuse/ignition feed.
- Measure continuity from the switch output to the BCM input connector. Repair any open or high-resistance circuit found.
- If wiring and switch appear correct, monitor BCM input with scan tool while operating switch. If BCM does not see the change, suspect BCM input circuit or module fault.
- If switch continuity is faulty or intermittent, remove and replace the hazard switch. After replacement, clear codes and verify operation.
- If replacement switch does not restore normal operation and wiring is good, consider BCM repair/replacement or reprogramming per manufacturer procedures—confirm vehicular network health (CAN/LIN) first.
- After repairs, clear DTCs and perform a full function test: activate hazards, verify indicator flashing, and re-scan for stored codes or pending faults.
Likely causes
- Failed hazard switch (mechanical/electrical contacts)
- Connector pin corrosion or pushed-out terminal at switch harness
- Broken or shorted wire in dash harness (common at connector or behind switch)
- Faulty ground or missing 12 V supply to switch
- Intermittent CAN/LIN communication or BCM input fault
Fault status
Status
Hazard switch input not detected or out of specification; communication/input to Body Control Module failed.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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Code
B1744
Other
B — Body
Mirror Passenger Vertical Switch Circuit Short To Ground
Views:
UK: 14
EN: 17
RU: 14
AI status
Completed
Completed
100%
Causes
- Faulty hazard (emergency flasher) switch or internal contacts
- Open, shorted or intermittent wiring between switch and Body/BCM
- Corroded or loose connector at switch or body control module
- Blown fuse or faulty flasher/relay (if used separately)
- Water intrusion or contamination in the switch assembly
- Body/BCM (body control module) input circuit or internal failure
Symptoms
- Hazard/emergency flashers will not operate when switch is pressed
- Hazard indicator lamp on the instrument cluster does not illuminate or flash
- Turn signals may still operate normally (depending on vehicle wiring)
- DTC B1744 stored and warning lamp or message present on scan tool
- Intermittent operation of hazard lights (works sometimes, fails other times)
What to check
- Use a scan tool to read/record freeze frame and live data for the hazard switch and related BCM inputs
- Visually inspect the hazard switch for physical damage, contamination or fluid ingress
- Inspect related fuses and relays for continuity and correct rating
- Check switch connector for bent pins, corrosion or looseness; wiggle test while observing live data
- Measure battery voltage at the switch supply pin with ignition on (should be ~12 V)
- Perform continuity test between switch output and BCM input; check for shorts to ground or battery
Signal parameters
- Switch supply voltage: ~12 V (battery/ignition supply) with key ON
- Switch output: contact closure to ground or to a BCM input (voltage changes when pressed)
- Continuity/resistance across switch contacts: near 0 ohms when pressed, high/OL when released (spec dependent)
- Flasher control: pulsed output from BCM or flasher relay (check for pulsed 12 V to lamp circuit when activated)
- CAN/LIN: hazard switch status may be transmitted as a message/bit on the vehicle network (verify with a capable scan tool)
Diagnostic algorithm
- Read and record DTC(s) and live data with a diagnostic scan tool. Note whether the hazard switch status is reported and how it behaves when pressed.
- Visually inspect the switch and surrounding trim for damage or contamination. Check harness and connector for corrosion, broken pins, or water ingress.
- Check related fuses and relays for continuity. Replace any blown fuse with correct rating before further testing.
- With ignition ON, back-probe the switch connector: verify supply voltage (≈12 V) and that the switch output changes state when pressed. If no supply, trace to fuse/ignition feed.
- Measure continuity from the switch output to the BCM input connector. Repair any open or high-resistance circuit found.
- If wiring and switch appear correct, monitor BCM input with scan tool while operating switch. If BCM does not see the change, suspect BCM input circuit or module fault.
- If switch continuity is faulty or intermittent, remove and replace the hazard switch. After replacement, clear codes and verify operation.
- If replacement switch does not restore normal operation and wiring is good, consider BCM repair/replacement or reprogramming per manufacturer procedures—confirm vehicular network health (CAN/LIN) first.
- After repairs, clear DTCs and perform a full function test: activate hazards, verify indicator flashing, and re-scan for stored codes or pending faults.
Likely causes
- Failed hazard switch (mechanical/electrical contacts)
- Connector pin corrosion or pushed-out terminal at switch harness
- Broken or shorted wire in dash harness (common at connector or behind switch)
- Faulty ground or missing 12 V supply to switch
- Intermittent CAN/LIN communication or BCM input fault
Fault status
Status
Hazard switch input not detected or out of specification; communication/input to Body Control Module failed.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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Your experience will help others
+100 karma for a short comment :)
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Send to email