B2240

Code

Other B — Body

Rear Cargo Door Reset Switch Stuck (Short to Ground)

Brand: Other

Type: B — Body

Views: UK: 33 EN: 41 RU: 30

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Short to ground in the switch circuit (bare wire contacting chassis)
Failed or internally shorted rear cargo door reset switch
Corroded or water-intruded connector at the switch or harness
Pin pushed out or terminal contact damage at connector
Damage to wiring from hinge area, chafing, or previous repair
Aftermarket accessory wiring or modifications tied into same circuit

Symptoms

Cargo door/trunk may not reset or close properly
Cargo door ajar lamp or message displayed
Inability to lock/unlock cargo door remotely
DTC B2240 stored in BCM and possible related warnings
Intermittent operation of cargo door switch (depending on movement)

What to check

Scan BCM and confirm freeze frame, occurrence count, and whether code is current or historic
Visually inspect the cargo door switch, connector, wiring harness, and nearby grommets for corrosion, damage, or pin push-out
Backprobe the switch connector and measure signal voltage with ignition ON and with the switch actuated
Continuity check between switch signal pin and chassis ground with connector disconnected to see if circuit is shorted
Wiggle test the harness through the door hinge while observing signal to reproduce fault
Disconnect switch and see if code clears or changes (store results before clearing)

Signal parameters

Supply/Reference: typically 12 V (ignition ON) or BCM reference — confirm in vehicle manual
Expected switch signal: ~0 V (ground) when switch actuated (closed) or open-circuit/high when not actuated depending on design
Fault condition: signal pin held near 0 V (ground) when it should be high/open — indicates short to ground
Resistance: closed switch ≈ 0–1 Ω between signal and ground; open switch → very high/OL; wiring short to ground → continuity to chassis ground with connector removed
Typical thresholds (vehicle-specific): 10 kΩ = open/normal

Diagnostic algorithm

Read and record freeze frame data and related codes. Note whether code is current or pending.
Visually inspect switch, connector, harness boots, and grommet for water ingress, corrosion, or damage. Repair visible corrosion or damaged wiring.
With ignition OFF, disconnect the rear cargo door reset switch connector. Check for continuity between the signal pin and chassis ground. If continuity exists with connector disconnected, there is a wiring short to ground.
If no continuity, bench-test the switch: measure resistance between switch terminals while actuating. Replace switch if it shows internal short or incorrect behavior.
If wiring is shorted, trace harness toward BCM: open access panels, inspect along hinge, and separate sections of harness. Use a wire isolation method (disconnect intermediate connectors) to localize the short.
Backprobe the switch signal at the harness with ignition ON. Observe voltage with the switch open and closed. Compare to expected parameters. Wiggle the harness through door travel to reproduce intermittent faults.
If short persists and cannot be found visually, disconnect the harness at the BCM (if accessible) and check for continuity to ground at the BCM connector. If short disappears when BCM connector is disconnected, inspect wiring between BCM and switch. If short remains at BCM connector pin, suspect internal wiring short or BCM fault.
Repair identified wiring damage or replace the switch/connector. Apply dielectric grease to prevent future corrosion and ensure proper sealing at grommets.
After repairs, clear codes and perform several open/close cycles and a road/usage test to confirm the fault does not return.
If all wiring and switch check good and the signal is still incorrect at the BCM, consult manufacturer service information for BCM test procedures or consider BCM replacement as a last resort.