Engine-Codes - Mercury - B121B MERCURY

B121B MERCURY Code - Keypad Input Switch

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

|B121B MERCURY code possible causes

  • 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 is the B121B MERCURY code repair?

Start by checking 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.

|B121B MERCURY 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 B121B MERCURY code

Labor: 1.0

The cost to diagnose the B121B MERCURY code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

|What are B121B MERCURY code possible symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

|What is B121B MERCURY code meaning?

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.

|Need more information with the B121B MERCURY code?

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