B2721
PASS-Key Detection Circuit
B2721 is an OBD-II diagnostic trouble code meaning: PASS-Key Detection Circuit. Common causes: open or short circuit in the wiring harness of the pass-key circuit, key reader antenna malfunction. Estimated repair cost: $56–167.
Symptoms
- Engine won't start
- Engine stalls after starting
- The immobilizer indicator is flashing
- A security system malfunction message appears on the dashboard
Causes
- Open or short circuit in the wiring harness of the PASS-Key circuit
- Key reader antenna malfunction
- Damage to the chip in the ignition key
- Immobilizer ECU malfunction
- Poor contact in PASS-Key system connectors
How to Fix
- Check the integrity of the PASS-Key circuit wiring harness
- Check the key reader antenna for damage
- Check the chip in the ignition key (try another key)
- Check connectors and contacts of the PASS-Key system
- Scan the immobilizer ECU for errors
- If necessary, replace faulty components
Related codes
FAQ
What does the B2721 code mean?
B2721 is an OBD-II diagnostic trouble code that indicates: PASS-Key Detection Circuit
What causes a B2721 error code?
The most common causes of B2721 include: Open or short circuit in the wiring harness of the PASS-Key circuit; Key reader antenna malfunction; Damage to the chip in the ignition key; Immobilizer ECU malfunction.
How do I fix a B2721 diagnostic trouble code?
To fix B2721: Check the integrity of the PASS-Key circuit wiring harness. Check the key reader antenna for damage. Check the chip in the ignition key (try another key). For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B2721?
Yes, but get it checked soon
How much does it cost to fix B2721?
The estimated repair cost for B2721 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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