OBD Code B1692: Autolamp Delay Circuit Short To Ground

Q: What does OBD code B1692 mean?

Autolamp Delay Circuit Short To Ground. The autolamp delay circuit has an unwanted electrical connection to ground, preventing the headlight delay module from functioning properly. Think of it like a water pipe with a hole drilled in it—the electrical signal leaks away instead of reaching its destination.

Q: How do I fix OBD fault code B1692?

Inspect the autolamp module connector for moisture, corrosion, or loose pins and clean or reseat as needed.. Check the autolamp circuit wiring for cuts, abrasions, or damaged insulation that could cause grounding.. Replace the autolamp module if wiring and connectors are intact and fault persists.

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What This Actually Means

In plain language — no jargon

The autolamp delay circuit has an unwanted electrical connection to ground, preventing the headlight delay module from functioning properly. Think of it like a water pipe with a hole drilled in it—the electrical signal leaks away instead of reaching its destination.

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Symptoms You May Notice

3 known symptoms for this code

Headlights do not turn off automatically after engine shutdown

Dashboard warning light illuminated for lamp/lighting system

Autolamp delay feature completely non-functional

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Embedded Systems Insight

What the ECU/ECM is actually computing

The ECU monitors the autolamp delay circuit voltage to verify it maintains proper signal integrity. When the circuit shorts to ground, the voltage drops near 0V instead of holding at expected reference levels. The ECU detects this abnormal low-voltage condition and sets the fault code.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Autolamp delay circuit voltage	5-12V (module-dependent)	<0.5V (short to ground detected)
Signal continuity resistance	>1000 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 module connector for moisture, corrosion, or loose pins and clean or reseat as needed.

2

Wiring and insulation

Check the autolamp circuit wiring for cuts, abrasions, or damaged insulation that could cause grounding.

3

Autolamp delay module

Replace the autolamp module if wiring and connectors are intact and fault persists.