Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1C42 — Trunk release switch 2

B1C42 — Trunk release switch 2

Detailed page for trouble code B1C42.

33,916codes
59brands
11,455generic
22,461specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

B1C42

LAND ROVER B — Body

Trunk release switch 2

Brand: LAND ROVER
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty trunk/boot release switch (switch 2)
  • Open or shorted wiring in the trunk release circuit
  • Poor or corroded connector at the switch or BCM
  • Water ingress or physical damage to switch/harness
  • Body control module (BCM) input fault or software issue
  • Aftermarket installations or recent repairs that disturbed wiring

Symptoms

  • Trunk release (remote or interior button) does not operate or is intermittent
  • Instrument panel shows trunk open or trunk release warning
  • Trunk may open unexpectedly or fail to latch
  • Trunk light or interior courtesy light may behave erratically
  • Parasitic battery drain in some cases

What to check

  • Read live data and freeze frame with a diagnostic scanner; note event frequency and conditions
  • Attempt to reproduce the fault by operating trunk release switches and remote
  • Inspect trunk release switch, surrounding trim and connector for corrosion, damage or water ingress
  • Visually inspect wiring from trunk lid to body (flex point) for chafing or breaks
  • Perform wiggle test on wiring and connector while monitoring the BCM input with a scanner or multimeter
  • Measure voltages and continuity at the switch connector with ignition and trunk conditions per service manual

Signal parameters

  • Typical behavior: switch is a momentary contact to ground or to a pull-up feed. Unpressed = pull-up voltage (~battery voltage or module reference), Pressed = ~0 V to chassis ground (verify for specific model)
  • Closed switch resistance: low (≈0–5 Ω) between contact and ground when pressed
  • Open switch resistance: high or infinite (>10 kΩ / OL) when not pressed
  • Expected signal transitions: clean, stable change when switch actuated; no rapid bouncing or intermittent drops
  • If using scan tool, watch the trunk switch input status bit: should change state only when switch is operated

Diagnostic algorithm

  1. Use a diagnostic scanner to confirm B1C42, capture freeze frame and check for related codes (other trunk or BCM faults).
  2. Attempt to reproduce the fault while monitoring live data. Note whether the input changes state and whether it is intermittent.
  3. Visually inspect the trunk release switch, surrounding trim, and connector for corrosion, water, or damage. Remove switch to inspect terminals.
  4. With connector disconnected, measure continuity/resistance of the switch between its terminals while operating it. Compare to expected (closed ≈ low ohms, open ≈ high ohms).
  5. Back-probe the switch connector with the ignition in the required state and the trunk switch unpressed: verify presence of pull-up/reference voltage at the signal pin (or correct idle state per vehicle documentation). Press the switch and verify the signal goes to ground or changes as expected.
  6. Perform a continuity/insulation check from the switch signal wire back to the BCM connector to detect opens or shorts. Wiggle the harness through the trunk hinge range while watching the signal for intermittent changes.
  7. Inspect and test related grounds and fuses. Repair any damaged wiring, clean/replace corroded connectors, and secure harness routing.
  8. If wiring and switch test good, inspect BCM connector pins for damage and consider BCM input testing or reflash per manufacturer procedures.
  9. After repairs, clear codes and verify functionality with repeated operation and a final scan to ensure B1C42 does not return.
  10. If code persists after harness and switch replacement, consult manufacturer service information for module bench testing or replacement.

Likely causes

  • Corroded/loose connector at trunk release switch
  • Broken or chafed wire in the trunk lid harness (flex point)
  • Switch contacts stuck or contaminated (moisture/debris)
  • Short to ground or battery voltage on the switch feed
  • Intermittent BCM input due to internal fault or poor ground

Fault status

⚠️ Status
Trunk release switch 2 circuit — open/short/intermittent signal detected by BCM.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1C40 B1C41 B1C43 B1C44 B1C4A
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

B1C42

MITSUBISHI B — Body

PS.lap pretensioner circuit low

Brand: MITSUBISHI
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty trunk/boot release switch (switch 2)
  • Open or shorted wiring in the trunk release circuit
  • Poor or corroded connector at the switch or BCM
  • Water ingress or physical damage to switch/harness
  • Body control module (BCM) input fault or software issue
  • Aftermarket installations or recent repairs that disturbed wiring

Symptoms

  • Trunk release (remote or interior button) does not operate or is intermittent
  • Instrument panel shows trunk open or trunk release warning
  • Trunk may open unexpectedly or fail to latch
  • Trunk light or interior courtesy light may behave erratically
  • Parasitic battery drain in some cases

What to check

  • Read live data and freeze frame with a diagnostic scanner; note event frequency and conditions
  • Attempt to reproduce the fault by operating trunk release switches and remote
  • Inspect trunk release switch, surrounding trim and connector for corrosion, damage or water ingress
  • Visually inspect wiring from trunk lid to body (flex point) for chafing or breaks
  • Perform wiggle test on wiring and connector while monitoring the BCM input with a scanner or multimeter
  • Measure voltages and continuity at the switch connector with ignition and trunk conditions per service manual

Signal parameters

  • Typical behavior: switch is a momentary contact to ground or to a pull-up feed. Unpressed = pull-up voltage (~battery voltage or module reference), Pressed = ~0 V to chassis ground (verify for specific model)
  • Closed switch resistance: low (≈0–5 Ω) between contact and ground when pressed
  • Open switch resistance: high or infinite (>10 kΩ / OL) when not pressed
  • Expected signal transitions: clean, stable change when switch actuated; no rapid bouncing or intermittent drops
  • If using scan tool, watch the trunk switch input status bit: should change state only when switch is operated

Diagnostic algorithm

  1. Use a diagnostic scanner to confirm B1C42, capture freeze frame and check for related codes (other trunk or BCM faults).
  2. Attempt to reproduce the fault while monitoring live data. Note whether the input changes state and whether it is intermittent.
  3. Visually inspect the trunk release switch, surrounding trim, and connector for corrosion, water, or damage. Remove switch to inspect terminals.
  4. With connector disconnected, measure continuity/resistance of the switch between its terminals while operating it. Compare to expected (closed ≈ low ohms, open ≈ high ohms).
  5. Back-probe the switch connector with the ignition in the required state and the trunk switch unpressed: verify presence of pull-up/reference voltage at the signal pin (or correct idle state per vehicle documentation). Press the switch and verify the signal goes to ground or changes as expected.
  6. Perform a continuity/insulation check from the switch signal wire back to the BCM connector to detect opens or shorts. Wiggle the harness through the trunk hinge range while watching the signal for intermittent changes.
  7. Inspect and test related grounds and fuses. Repair any damaged wiring, clean/replace corroded connectors, and secure harness routing.
  8. If wiring and switch test good, inspect BCM connector pins for damage and consider BCM input testing or reflash per manufacturer procedures.
  9. After repairs, clear codes and verify functionality with repeated operation and a final scan to ensure B1C42 does not return.
  10. If code persists after harness and switch replacement, consult manufacturer service information for module bench testing or replacement.

Likely causes

  • Corroded/loose connector at trunk release switch
  • Broken or chafed wire in the trunk lid harness (flex point)
  • Switch contacts stuck or contaminated (moisture/debris)
  • Short to ground or battery voltage on the switch feed
  • Intermittent BCM input due to internal fault or poor ground

Fault status

⚠️ Status
Trunk release switch 2 circuit — open/short/intermittent signal detected by BCM.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1C40 B1C41 B1C43 B1C44 B1C4A
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .