AutoCodes – RAM – B1E99 RAM

B1E99 RAM Code - Front Left Heater Control Circuit

Quick Answer

The Comfort Seat Wheel Module (CSWM) monitors the Front Left Heater Control Circuit. Common causes include Faulty Front Left Seat Back Heater Element, Front Left Seat Back Heater Element harness is open or shorted, Front Left Seat Back Heater Element circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B1E99 RAM indicates Front Left Heater Control Circuit.
Common causes: Common causes include Faulty Front Left Seat Back Heater Element, Front Left Seat Back Heater Element harness is open or shorted, Front Left Seat Back Heater Element circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,818

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Sep 04, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B1E99 RAM Description

The Comfort Seat Wheel Module (CSWM) monitors the Front Left Heater Control Circuit. The CSWM sets the OBDII code when the CSWM detects on the Left Front Seat Heater Control circuit an impedance equal to or above 7.0 Ohms for more than two seconds, a voltage below 1.0 volt or a current above 10.0 amps for more than two seconds with the output turned on, a voltage above 5.0 volts for more than two seconds with the output turned off or a current below 0.5 of an amp for more than two seconds with the output turned on.

OBDII Code B1E99 RAM - Front Left Heater Control Circuit - AutoCodes.com — B1E99 RAM Code - Front Left Heater Control Circuit

What does this mean?

What are the Possible Causes of the DTC B1E99 RAM?

Faulty Front Left Seat Back Heater Element
Front Left Seat Back Heater Element harness is open or shorted
Front Left Seat Back Heater Element circuit poor electrical connection
Faulty Comfort Seat Wheel Module (CSWM)

How to Fix the DTC B1E99 RAM?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

B1E99-1E FRONT LEFT HEATER CONTROL CIRCUIT RESISTANCE OUT OF RANGE
B1E99-11 FRONT LEFT HEATER CONTROL CIRCUIT SHORT TO GROUND
B1E99-12 FRONT LEFT HEATER CONTROL CIRCUIT SHORT TO BATTERY
B1E99-13 FRONT LEFT HEATER CONTROL CIRCUIT OPEN

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1E99 RAM code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B1E99 RAM Code

1. What does OBDII code B1E99 mean on a RAM vehicle?

Code B1E99 indicates an issue with the Front Left Heater Control Circuit, which is responsible for regulating the heating system on the driver's side.

2. What are the common symptoms of B1E99 in a RAM vehicle?

Symptoms may include no heat or inconsistent heating on the front left side, unresponsive temperature controls, or a check engine or HVAC warning light.

3. What causes the B1E99 Front Left Heater Control Circuit code?

Common causes include a faulty heater actuator, damaged wiring or connectors in the circuit, or a malfunctioning HVAC control module.

4. How is the B1E99 code diagnosed?

A technician will use a scan tool to confirm the code, inspect the heater control circuit for damaged wiring, test the actuator's operation, and check for faults in the HVAC control module.

5. Can I still drive my RAM with a B1E99 code?

Yes, you can drive with this code, but the heating system on the driver's side may not work properly, which can be uncomfortable in cold weather.

6. How do I fix the B1E99 code on my RAM?

Repairs may involve replacing the faulty heater actuator, repairing or replacing damaged wiring or connectors, or reprogramming or replacing the HVAC control module.

7. How much does it cost to repair the B1E99 code?

The cost varies, but replacing a heater actuator typically ranges from $150 to $400, depending on parts and labor. Wiring repairs may cost less if no major components need replacement.

8. Can I fix the B1E99 code myself?

If you have experience with electrical systems, you may be able to inspect and repair wiring or replace the heater actuator. However, advanced diagnostics may require professional equipment.

9. What tools are needed to diagnose the B1E99 code?

Youâ€™ll need an OBDII scan tool, a multimeter for testing electrical connections, and possibly a repair manual specific to your RAM model.

10. Will clearing the B1E99 code solve the problem?

Clearing the code without fixing the underlying issue will only temporarily remove the warning. The code will likely return until the root cause is addressed.