B2555

Code

Other B — Body

LAMP DOME OUTPUT Circuit Short to Battery

Brand: Other

Type: B — Body

Views: UK: 26 EN: 47 RU: 45

AI status

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Page language: EN

Causes

Damaged or chafed wiring contacting a constant 12V source
Shorted dome/interior lamp or socket (internal short)
Faulty or stuck door/dome lamp switch or connector shorted to battery
Aftermarket accessory or auxiliary wiring tied into the dome lamp circuit incorrectly
Corroded or bridged connector terminals allowing battery feed to the circuit
Internal fault in the body control module / instrument panel control module

Symptoms

Interior/dome lamp(s) remain on or come on unexpectedly
Battery drain or dead battery after vehicle sits
Dome lamp will not turn off with dome switch or doors closed
Door-ajar or interior light indicator may behave incorrectly
Possible blown interior lighting fuse if excessive current

What to check

Obtain wiring diagram for dome/interior lamp circuit and identify related connectors, switches, and fuses
Visually inspect wiring, lamp sockets, connectors, and door jamb switches for corrosion, damage, or signs of aftermarket splices
Verify fuse condition and fuse box connections for the dome lamp circuit
With ignition off, measure voltage at the dome lamp connector and at the BCM output pin to see if battery voltage is present when circuit should be off
Disconnect interior lamps/individual sockets and recheck circuit to isolate downstream power feed
Check for aftermarket devices (alarms, stereos, convenience modules) tied into interior lighting

Signal parameters

Expected voltage at dome output: ~0 V when OFF, ~11–14 V when ON (vehicle battery nominal)
If short to battery fault is present: ~11–14 V measured at dome output with circuit commanded OFF
Typical lamp current when ON: hundreds of milliamps (depends on number/type of bulbs/LEDs); current when OFF should be near zero (microamps to a few mA for module standby)
Resistance from dome output to battery positive when circuit OFF: should be very high (open); low resistance indicates short to battery

Diagnostic algorithm

Record symptom details and any related DTCs; ensure doors and dome switch are in known positions.
Visually inspect lamp sockets, harness routing, and door switch areas for damage, corrosion, or aftermarket splices. Repair obvious damage.
With ignition OFF, measure DC voltage at the dome lamp connector and at the BCM output pin. If ~12 V is present with BCM disconnected, the short is downstream of the BCM.
Disconnect each interior lamp/LED module and retest voltage/current to isolate the affected branch. Remove bulbs to see if fault clears.
If circuit voltage disappears when the harness is disconnected from the vehicle body connectors, isolate to that connector/wiring segment and repair/replace as needed.
If all downstream wiring checks good and voltage remains present only when BCM is connected, perform BCM connector inspection and wiggle tests; backprobe BCM output while commanding dome lamp ON/OFF using scan tool to observe behavior.
Verify door/dome switch operation; replace or clean switches/sockets if mechanically stuck or shorted.
Repair any shorted wiring, corroded connectors, or replace faulty lamps. After repairs, clear codes and confirm the DTC does not return and that lamp behaves correctly.
If wiring and components are confirmed good and fault persists, consider BCM replacement or repair following manufacturer procedures (module programming may be required).

Likely causes

Shorted lamp socket (moisture/corrosion)
Accessory or alarm wiring connected to dome lamp circuit
Chafed harness contacting a fused, constant 12V feed
Faulty door switch mechanically stuck closed or shorted connector
BCM internal driver failure (less common)

Fault status

⚠️ Status

Body control module reports that the dome/interior lamp output circuit is receiving battery voltage when it should be off (short-to-battery detected).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 Hours