Code
B1742
MITSUBISHI
B — Body
Turn signal switch fail
Views:
UK: 5
EN: 9
RU: 11
AI status
Completed
Completed
100%
Causes
- Faulty turn signal / combination switch (mechanical or internal electrical failure)
- Damaged or corroded connector at the switch or BCM
- Open, shorted or intermittent wiring in the turn‑signal circuit
- Poor ground or supply voltage to the switch
- Faulty body/BCM input circuit or internal module fault
- Water ingress or contamination inside the switch assembly
Symptoms
- Turn signals fail to operate on one or both sides
- Indicators on dash do not respond or behave erratically (rapid flash, no flash, steady on)
- Hazard lights may not work or operate inconsistently
- Cancel function may not return the lever to neutral
- Intermittent operation or operation only when steering column is moved
- Related steering column functions (e.g., wipers, lights) may show faults if integrated
What to check
- Verify customer complaint and attempt to reproduce fault with key on/engine off and engine running
- Scan BCM/vehicle network for related DTCs and check freeze frame/live data
- Visually inspect turn signal switch assembly and steering column for damage or moisture
- Inspect connectors for corrosion, bent pins, or loose terminals at the switch and BCM
- Check related fuses and relays for continuity and correct operation
- Perform wiggle test of harness while observing operation or live data
Signal parameters
- Switch supply voltage (key ON): ~12 V at power feed terminal
- Ground: near 0 Ω to chassis ground with continuity test
- Switch output terminals: close to 12 V (active) or open/near 0 V depending on circuit design
- Open circuit or high resistance when switch is in neutral (depends on design)
- Flasher output: pulsed voltage ~12 V when functional (pulse frequency typically ~1 Hz)
- If CAN/lin network present: switch state messages present on network when actuated (use a vehicle scanner)
Diagnostic algorithm
- Confirm the complaint and record conditions (symptoms, when it occurs, steering wheel position)
- Scan the vehicle and note all related codes; freeze frame/live data can show when the fault sets
- Visually inspect the switch, steering column, harness and connectors for damage, corrosion or moisture
- Check fuses and relays for the turn signal circuit and replace if faulty
- With ignition ON, measure supply voltage and ground at the turn signal switch connector; compare to expected values
- Operate the switch while measuring outputs; verify continuity/resistance changes or presence of 12 V on output pins when activated
- Perform a wiggle/position test on the column harness and switch while observing outputs to find intermittent wiring faults
- If outputs are correct at the switch but module still reports fault, inspect harness back to BCM and measure for continuity/shorts to ground/power
- If wiring and connectors are good and switch outputs are abnormal, replace the combination/turn signal switch assembly
- If replacement does not clear the code, suspect BCM input circuit fault; verify BCM power/ground and consult manufacturer repair data for module testing
- Clear codes and retest to confirm repair; perform full function check of turn signals and hazards
Likely causes
- Worn or internally failed turn signal/combination switch
- Loose/corroded connector at the switch or steering column harness
- Broken or chafed wiring between switch and body control module
- Poor ground or supply to the switch
Fault status
Status
Malfunction detected in the turn signal (combination) switch circuit — electrical or mechanical failure of the switch or its wiring/connector is possible.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
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
B1742
Other
B — Body
Mirror Passenger Vertical Switch Circuit Open
Views:
UK: 18
EN: 17
RU: 23
AI status
Completed
Completed
100%
Causes
- Faulty turn signal / combination switch (mechanical or internal electrical failure)
- Damaged or corroded connector at the switch or BCM
- Open, shorted or intermittent wiring in the turn‑signal circuit
- Poor ground or supply voltage to the switch
- Faulty body/BCM input circuit or internal module fault
- Water ingress or contamination inside the switch assembly
Symptoms
- Turn signals fail to operate on one or both sides
- Indicators on dash do not respond or behave erratically (rapid flash, no flash, steady on)
- Hazard lights may not work or operate inconsistently
- Cancel function may not return the lever to neutral
- Intermittent operation or operation only when steering column is moved
- Related steering column functions (e.g., wipers, lights) may show faults if integrated
What to check
- Verify customer complaint and attempt to reproduce fault with key on/engine off and engine running
- Scan BCM/vehicle network for related DTCs and check freeze frame/live data
- Visually inspect turn signal switch assembly and steering column for damage or moisture
- Inspect connectors for corrosion, bent pins, or loose terminals at the switch and BCM
- Check related fuses and relays for continuity and correct operation
- Perform wiggle test of harness while observing operation or live data
Signal parameters
- Switch supply voltage (key ON): ~12 V at power feed terminal
- Ground: near 0 Ω to chassis ground with continuity test
- Switch output terminals: close to 12 V (active) or open/near 0 V depending on circuit design
- Open circuit or high resistance when switch is in neutral (depends on design)
- Flasher output: pulsed voltage ~12 V when functional (pulse frequency typically ~1 Hz)
- If CAN/lin network present: switch state messages present on network when actuated (use a vehicle scanner)
Diagnostic algorithm
- Confirm the complaint and record conditions (symptoms, when it occurs, steering wheel position)
- Scan the vehicle and note all related codes; freeze frame/live data can show when the fault sets
- Visually inspect the switch, steering column, harness and connectors for damage, corrosion or moisture
- Check fuses and relays for the turn signal circuit and replace if faulty
- With ignition ON, measure supply voltage and ground at the turn signal switch connector; compare to expected values
- Operate the switch while measuring outputs; verify continuity/resistance changes or presence of 12 V on output pins when activated
- Perform a wiggle/position test on the column harness and switch while observing outputs to find intermittent wiring faults
- If outputs are correct at the switch but module still reports fault, inspect harness back to BCM and measure for continuity/shorts to ground/power
- If wiring and connectors are good and switch outputs are abnormal, replace the combination/turn signal switch assembly
- If replacement does not clear the code, suspect BCM input circuit fault; verify BCM power/ground and consult manufacturer repair data for module testing
- Clear codes and retest to confirm repair; perform full function check of turn signals and hazards
Likely causes
- Worn or internally failed turn signal/combination switch
- Loose/corroded connector at the switch or steering column harness
- Broken or chafed wiring between switch and body control module
- Poor ground or supply to the switch
Fault status
Status
Malfunction detected in the turn signal (combination) switch circuit — electrical or mechanical failure of the switch or its wiring/connector is possible.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
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