OBD Code B1695: Autolamp On Circuit Short To Battery

Q: What does OBD code B1695 mean?

Autolamp On Circuit Short To Battery. The autolamp (automatic headlight) control circuit is shorted directly to battery voltage, meaning it's receiving too much electrical power. Think of it like a water pipe that's supposed to have controlled flow but instead has a direct line to the main supply—the system can't regulate it properly.

Q: What are the symptoms of fault code B1695?

Headlights stay on continuously or flicker unexpectedly, Dashboard warning light illuminated or autolamp feature inoperative, Battery drains faster than normal due to constant lamp draw

Q: How do I fix OBD fault code B1695?

Inspect the autolamp connector for corrosion, damaged pins, or moisture and clean or reseat the connection.. Test and replace the autolamp relay if it is stuck in the on position or has internal short.. Check for pinched, chafed, or damaged wiring between the relay, module, and headlamp assembly and repair or replace as needed.

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What This Actually Means

In plain language — no jargon

The autolamp (automatic headlight) control circuit is shorted directly to battery voltage, meaning it's receiving too much electrical power. Think of it like a water pipe that's supposed to have controlled flow but instead has a direct line to the main supply—the system can't regulate it properly.

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Symptoms You May Notice

3 known symptoms for this code

Headlights stay on continuously or flicker unexpectedly

Dashboard warning light illuminated or autolamp feature inoperative

Battery drains faster than normal due to constant lamp draw

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Embedded Systems Insight

What the ECU/ECM is actually computing

The ECU monitors the autolamp control circuit voltage, expecting it to cycle between ground and a moderate supply voltage based on ambient light sensor input. When the circuit shorts directly to battery voltage, the ECU detects an abnormally high voltage level that exceeds the normal operating threshold, triggering the fault code.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Autolamp circuit voltage	0V to 5V (modulated by sensor)	>10V (shorted to battery rail)
Control module output resistance	100-10k ohms	<10 ohms (short condition)

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Wiring harness connector

Inspect the autolamp connector for corrosion, damaged pins, or moisture and clean or reseat the connection.

2

Autolamp relay

Test and replace the autolamp relay if it is stuck in the on position or has internal short.

3

Autolamp control wiring

Check for pinched, chafed, or damaged wiring between the relay, module, and headlamp assembly and repair or replace as needed.