B1D21 Code - Remote Control Switch Signal Compare Failure
Quick Answer
The Body Control Module (BCM) monitors the Remote Control Switch. Common causes include Faulty Remote Control Switch, Remote Control Switch harness is open or shorted, Remote Control Switch 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
- B1D21 indicates Remote Control Switch Signal Compare Failure.
- Common causes
- Common causes include Faulty Remote Control Switch, Remote Control Switch harness is open or shorted, Remote Control Switch 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.
Code B1D21 Description
What are the Possible Causes of the DTC B1D21?
- Faulty Remote Control Switch
- Remote Control Switch harness is open or shorted
- Remote Control Switch circuit poor electrical connection
- Faulty Body Control Module (BCM)
How to Fix the DTC B1D21?
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 B1D21 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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Information for Specific Makes
- B1D21 Chrysler — Mirror Vertical Motor Control Circuit Open
- B1D21 Dodge — Mirror Vertical Motor Control Circuit Open
- B1D21 Ford — Remote Control Switch Signal Compare Failure
- B1D21 Jeep — Mirror Vertical Motor Control Circuit Open
- B1D21 Lincoln — Remote Control Switch Signal Compare Failure
- B1D21 Mercury — Remote Control Switch Signal Compare Failure
- B1D21 RAM — Mirror Vertical Motor Control Circuit Open
Frequently Asked Questions about B1D21 Code
1. What does the OBDII code B1D21 mean?
B1D21 indicates a Remote Control Switch Signal Compare Failure, meaning there is a mismatch or issue with the signals from the remote control switch.
2. What are the common symptoms of the B1D21 code?
Typical symptoms include the remote key fob not working, failure to lock or unlock doors remotely, and intermittent operation of keyless entry features.
3. What causes the B1D21 code to appear?
This code can be caused by a faulty remote control switch, a weak or dead key fob battery, damaged wiring, or a malfunctioning receiver module.
4. Can a low key fob battery trigger the B1D21 code?
Yes, a weak or dead key fob battery can cause signal issues and lead to the B1D21 code.
5. How do I diagnose the B1D21 code?
Start by checking the key fob battery, inspecting the wiring and connectors for damage, and testing the remote control switch for proper operation using a scan tool.
6. How is the B1D21 code fixed?
Repairs might include replacing the key fob battery, repairing damaged wiring, reprogramming the remote control switch, or replacing the receiver module if faulty.
7. Can I still drive my car with the B1D21 code?
Yes, the B1D21 code does not typically affect drivability, but keyless entry features may not function properly.
8. Do I need to reprogram the key fob to fix the B1D21 code?
In some cases, reprogramming the key fob may be necessary if the signal is not being recognized correctly by the system.
9. How much does it cost to repair the B1D21 code?
Repair costs vary but typically range from $50 to $200, depending on whether you need a new key fob or repairs to the receiver module or wiring.
10. Can a software update fix the B1D21 code?
In rare cases, a software update to the vehicle’s control module may resolve the issue if it’s related to a software glitch.
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