Left Headlamp Leveling Motor Control Circuit Performance
Table of contents
B1685 RAM Possible Causes
- Faulty Left Headlamp Leveling Motor
- Left Headlamp Leveling Motor harness is open or shorted
- Left Headlamp Leveling Motor circuit poor electrical connection
- Faulty Automatic Headlamp Leveling Module (AHLM)
How do I fix code B1685 RAM?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the B1685 RAM code
The cost of diagnosing the B1685 RAM code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B1685 RAM Description
The Front and Rear Headlamp Level Sensors monitor changes in the relative distance between the vehicle body and the front or rear suspension members. In vehicles with High Intensity Discharge (HID) Headlamps but without the air suspension system, the sensor circuitry is energized by the Automatic Headlamp Leveling Module (AHLM) and both sensors provide hard wired inputs back to the AHLM. The AHLM uses these sensor inputs as logic for calculating when and how much to adjust the headlamp beams as part of the Automatic Headlamp Leveling feature. The Automatic Headlamp Leveling Module (AHLM) detects a short to voltage, short to ground, or an open on the LIN Lighting circuit.