AutoCodes – Lincoln – B121B Lincoln

B121B Lincoln Code - Keypad Input Switch

Quick Answer

The keypad feature operates independently of key position status, vehicle speed, or transmission position. Common causes include Faulty Keypad Input Switch, Keypad Input Switch harness is open or shorted, Keypad Input Switch circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B121B Lincoln indicates Keypad Input Switch.
Common causes: Common causes include Faulty Keypad Input Switch, Keypad Input Switch harness is open or shorted, Keypad Input Switch circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 1,322

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 19, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B121B Lincoln Description

The keypad feature operates independently of key position status, vehicle speed, or transmission position. When a keypad button is touched, the keypad buttons illuminate to provide better visibility. The keypad is also illuminated any time that the courtesy lighting is on. If the lock all doors command is entered or 5 seconds have elapsed since the last button press, the illumination is turned off. Each vehicle equipped with a keypad is programmed with a 5-digit entry code. This code is provided to the customer through a wallet card in the Owner's Literature. In addition, this code is available through a scan tool and is also printed on the BCM label. When entering codes each digit must be entered within 5 seconds of the previous button press. A DTC that sets when the BCM detects a short to ground on any of the keyless entry keypad input circuits.

OBDII Code B121B Lincoln - Keypad Input Switch - AutoCodes.com — B121B Lincoln Code - Keypad Input Switch

What does this mean?

What are the Possible Causes of the DTC B121B Lincoln?

Faulty Keypad Input Switch
Keypad Input Switch harness is open or shorted
Keypad Input Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B121B Lincoln?

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

B121B:01 Keypad Input Switch General Electrical Failure
B121B:11 Keypad Input Switch Circuit Short To Ground

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B121B Lincoln 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 B121B Lincoln Code

1. What are the common symptoms of OBDII code B121B (Lincoln) related to the Keypad Input Switch?

The common symptoms include non-functional keypad buttons on the vehicle's exterior, difficulty locking/unlocking the vehicle using the keypad, and illuminated warning lights on the dashboard.

2. What could cause the OBDII code B121B (Lincoln) related to the Keypad Input Switch?

The code B121B is usually triggered by a malfunction in the keypad input switch itself, which could be due to wiring issues, a faulty switch, or water damage.

3. How can I diagnose the OBDII code B121B (Lincoln) related to the Keypad Input Switch?

Diagnosing this code involves inspecting the keypad wiring for any visible damage, testing the switch for continuity and proper operation, and checking for any signs of water intrusion or corrosion.

4. Can I repair the OBDII code B121B (Lincoln) related to the Keypad Input Switch on my own?

If you have experience with automotive electrical systems and the necessary tools, you may be able to repair this issue on your own by replacing the faulty keypad input switch or repairing any damaged wiring.

5. Are there any precautions to take when working on the Keypad Input Switch to fix OBDII code B121B (Lincoln)?

It's important to disconnect the vehicle's battery before working on the keypad input switch to prevent electrical shorts or damage. Additionally, ensure the area is dry and free from moisture to avoid further issues.

6. Will the OBDII code B121B (Lincoln) related to the Keypad Input Switch affect the vehicle's overall performance?

While the code itself may not directly impact the vehicle's performance, a malfunctioning keypad input switch can cause inconvenience and potential security concerns if you're unable to lock or unlock your vehicle effectively.

7. How urgent is it to address the OBDII code B121B (Lincoln) related to the Keypad Input Switch?

While the vehicle may still be drivable with this code present, it's advisable to address the issue promptly to ensure the keypad functions properly and to prevent any potential security risks associated with a malfunctioning switch.

8. Can the OBDII code B121B (Lincoln) related to the Keypad Input Switch cause any other problems in the vehicle?

If left unresolved, the code B121B could lead to further electrical issues or potential draining of the vehicle's battery due to the switch malfunctioning and drawing power when not in use.

9. Is resetting the OBDII code B121B (Lincoln) related to the Keypad Input Switch sufficient to fix the problem?

Resetting the code may temporarily clear the warning light, but it will not fix the underlying issue causing the B121B code. Proper diagnosis and repair of the keypad input switch are necessary to address the problem effectively.

10. How can I prevent the OBDII code B121B (Lincoln) related to the Keypad Input Switch from recurring in the future?

To prevent the code from recurring, regularly inspect the keypad input switch for any signs of wear or damage, avoid exposing it to water or moisture, and address any wiring issues promptly to maintain proper functionality.