AutoCodesGeneric – B1242

B1242 Code - Wireless Door Lock Tuner Circuit Malfunction

Quick Answer

The Door Control Receiver is used to receive radio waves related to the entry functions of the electrical key transmitter sub-assembly. Common causes include Faulty Door Control Receiver, Door Control Receiver harness is open or shorted, Door Control Receiver 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
B1242 indicates Wireless Door Lock Tuner Circuit Malfunction.
Common causes
Common causes include Faulty Door Control Receiver, Door Control Receiver harness is open or shorted, Door Control Receiver 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 27,580
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Nov 19, 2024
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Code B1242 Description

The Door Control Receiver is used to receive radio waves related to the entry functions of the electrical key transmitter sub-assembly. The certification ECU (smart key ECU assembly) decodes the requested electrical key transmitter sub-assembly operation by identifying a key code based on the radio waves received via the door control receiver. The door control receiver receives a signal from the electrical key transmitter sub-assembly and sends signals to the main body ECU (multiplex network body ECU) through the certification ECU (smart key ECU assembly). (For example, if a door lock operation is requested, the certification ECU [smart key ECU assembly] sends a door lock command to the main body ECU [multiplex network body ECU]).
OBDII Code B1242 - Wireless Door Lock Tuner Circuit Malfunction - AutoCodes.com
B1242 Code - Wireless Door Lock Tuner Circuit Malfunction

What are the Possible Causes of the DTC B1242?

  • Faulty Door Control Receiver
  • Door Control Receiver harness is open or shorted
  • Door Control Receiver circuit poor electrical connection
  • Faulty Certification ECU (Smart Key ECU Assembly)

How to Fix the DTC B1242?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1242 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.

Need more information about the B1242 code?

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Information for Specific Makes

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 B1242 Code

1. What does the OBDII code B1242 mean?

The code B1242 indicates a malfunction in the Wireless Door Lock Tuner Circuit, which is responsible for receiving signals from the key fob to lock or unlock the doors.

2. What are the common symptoms of code B1242?

Symptoms may include the remote key fob not working, doors failing to lock or unlock remotely, or intermittent operation of the wireless door lock system.

3. What causes the B1242 code to appear?

Common causes include a faulty wireless door lock receiver, damaged wiring or connectors in the circuit, interference from other electronic devices, or a malfunctioning key fob.

4. Can a dead key fob battery cause the B1242 code?

While a dead key fob battery won't directly trigger the B1242 code, it can cause symptoms similar to those of a circuit malfunction. Replacing the battery should be the first step before further diagnosis.

5. How can I fix the B1242 code?

Begin by checking the key fob battery, inspecting the wiring and connections in the wireless door lock circuit, and testing the wireless receiver module. Replace or repair components as necessary.

6. Is it safe to drive with the B1242 code?

Yes, the B1242 code does not affect the drivability of the vehicle, but it may compromise the convenience and security of the wireless door lock system.

7. How much does it cost to repair a B1242 code?

The repair cost can vary depending on the issue. Replacing a key fob battery is inexpensive, while replacing a wireless receiver module or repairing damaged wiring can cost $150–$500 or more.

8. Can environmental factors cause the B1242 code?

Yes, environmental interference, such as radio frequency signals from nearby devices or extreme temperatures, can temporarily affect the wireless door lock system and trigger this code.

9. Do I need to reprogram the key fob if the B1242 code is present?

Not necessarily. Reprogramming the key fob may help if the issue stems from a communication error, but it won't resolve issues with the tuner circuit itself.

10. Can I diagnose the B1242 code myself?

If you have basic tools like a multimeter and knowledge of automotive wiring, you can inspect for broken wires or loose connectors. However, diagnosing the wireless receiver module may require advanced tools and expertise.

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