B1575

Code

Other B — Body

Lamp Park Input Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 30 EN: 49 RU: 35

AI status

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Page language: EN

Causes

Burnt, loose or corroded bulb or bulb socket
Open, shorted or damaged wiring harness or connector to park lamp
Blown fuse or faulty relay in lighting circuit
Poor ground connection at lamp or BCM
Faulty BCM/lamp control module or internal input circuit failure
Aftermarket lighting or modifications causing incorrect load or wiring

Symptoms

One or more parking/side marker lamps do not illuminate (or flicker)
Illumination warning or lamp lamp indicator on dash
DTC B1575 stored in BCM or body module
Intermittent lamp operation that may change with vibration or connector movement

What to check

Scan for B1575 and any related codes; record freeze frame data and current lamp state
Visual inspection of affected lamp(s), sockets and harness for corrosion, damage or water intrusion
Check related fuses and relays
Inspect grounds and ensure tight, clean connections
Wiggle-test wiring and connectors while observing lamp operation or scan tool data
Measure voltage at lamp socket with lamp ON and OFF using a multimeter

Signal parameters

Park lamp input should read battery voltage (~11–14 V) at the lamp socket with the park lights switched ON
Park lamp input should be near 0 V (or open) with lights OFF unless circuit uses switched ground
Some vehicles use PWM dimming—expect a pulsed voltage rather than steady 12 V; frequency typically tens to hundreds of Hz
Resistance/open-circuit: continuity from socket to BCM input should be low (near 0 ohms) with connectors connected; open indicates break
Short to ground: very low resistance from circuit to chassis ground with harness disconnected indicates short
Short to battery: presence of constant battery voltage at BCM input with switch OFF indicates short/bypass

Diagnostic algorithm

Read and record all body-module DTCs and freeze frame; clear codes and see if B1575 returns.
Visually inspect the affected lamp(s), socket(s), and harness for corrosion, water, or damage. Replace corroded bulbs/sockets.
Verify fuses and relays for the park lamp circuit; replace any blown fuses and retest.
With ignition ON and lamps commanded ON, measure DC voltage at the lamp socket terminals. Note values ON vs OFF.
If no voltage at socket but fuse OK, trace voltage back toward BCM: inspect connectors and measure at intermediate harness plugs.
Check ground integrity: measure voltage drop between lamp ground and chassis ground while lamp is ON; large drop indicates poor ground.
With battery disconnected, check continuity between lamp socket and BCM input pin. Repair any open circuits.
Check for shorts: with battery disconnected, measure resistance from circuit to ground and to battery positive to identify short paths.
If PWM or CAN-controlled lighting is suspected, monitor the BCM input with a scope or scan-tool data to verify expected waveform.
Repair or replace damaged wiring, connectors, sockets, or bulbs. Reconnect and clear codes. Verify repair by cycling lights and road test.
If wiring and lamp hardware are good and the fault persists, verify BCM software and inputs; consult manufacturer repair information before replacing BCM. Replace BCM only after all wiring and components are proven good.

Likely causes

Blown bulb or corroded bulb socket
Open or short in the park lamp wiring or poor connector contact
Loose or corroded ground at the lamp or body ground point
Faulty BCM input (less common) or incorrect aftermarket wiring

Fault status

⚠️ Status

Lamp Park Input Circuit Failure — the lamp input circuit to the body control module is reporting open, short, incorrect voltage or intermittent signal. Check lamp, wiring, connectors, fuses/relays and module input.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours