B2960 on Chevrolet
Key/Immobilizer Communication Error
B2960 on Chevrolet vehicles indicates key/immobilizer communication error. Au7o has documented this code across 5 Chevrolet models — most commonly on Cavalier, Colorado, HHR. B2960 is a body/security code indicating a key or immobilizer (anti-theft) communication error, where the security module read sensor or key data that appears valid in form but does not match the expected, previously learned value. On many vehicles this involves a Passlock or transponder/immobilizer check that must pass before the computer allows the engine to start. When it fails, you typically get a security/anti-theft warning light and a no-start or no-crank condition. This is a manufacturer-specific code tied to the theft-deterrent system rather than an engine mechanical fault. Typical repair costs on Chevrolet range from $50 to $800, depending on the specific model and root cause.
Common Causes of B2960
- •Faulty Passlock/ignition lock cylinder sensor
- •Damaged or worn transponder key or key chip
- •Wiring or connector fault in the security sensor circuit
- •Body control module (BCM) failure or needs relearn
- •Incomplete or lost immobilizer/key relearn procedure
- •Worn ignition lock cylinder
- •Aftermarket alarm or remote-start interference
B2960 on Chevrolet by Model
Chevrolet Cavalier(1 issue)
- Passlock Anti-Theft System Prevents Starting2000-2005
The Passlock security system frequently malfunctions, reading the wrong resistance from the ignition cylinder sensor and refusing to allow the engine to start. The security light flashes and the car cranks but will not fire. This commonly occurs in cold weather or after the ignition cylinder wears internally.
Chevrolet Colorado(1 issue)
- Passlock Ignition Switch Failure Causing No-Start and Security Light2004-2012
First-generation Colorado/Canyon trucks commonly suffer from Passlock-related ignition switch failures that trigger a crank-no-start or start-and-stall condition with the security light illuminated. Owners often report the truck starting normally after a 10-minute relearn wait, then failing again later. GM issued service information on theft deterrent and ignition switch diagnosis, and the issue is widely documented in owner complaints and forums.
Chevrolet HHR(1 issue)
- Passlock Anti-Theft System No-Start (Security Light)2006-2011
The HHR uses GM's Passlock theft-deterrent system, and a failing Passlock sensor in the ignition lock cylinder commonly triggers a false theft condition. The 'Service Theft Deterrent System' message appears, the security light flashes, and the engine cranks but will not start (or will not crank), often intermittently. A weak battery or a worn lock cylinder/sensor are the usual culprits.
Chevrolet Impala(1 issue)
- Passlock Security System No-Start Condition2000-2005
The Passlock anti-theft system causes intermittent no-start conditions where the security light flashes and the fuel pump is disabled. The ignition lock cylinder contains a Hall-effect sensor that reads a resistance value; when contacts wear or corrode, the BCM detects a mismatch and locks out fuel delivery. The problem typically worsens progressively from occasional to daily. 225+ complaints were filed for the 2002 model year alone.
Chevrolet Malibu(1 issue)
- Passlock Anti-Theft System Causing No-Start and Intermittent Stalling2000-2005
A common failure on early-2000s Malibu models is the Passlock security system falsely detecting a theft condition, which can disable fuel delivery and prevent the engine from starting. Owners report the SECURITY light flashing, long wait times before restart, and in some cases intermittent stalling or crank-no-start behavior. The root cause is typically failure in the ignition lock cylinder sensor/housing or related wiring causing incorrect resistance/voltage readings to the body control module.
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View B2960 across all makes →Frequently Asked Questions
What does B2960 mean on Chevrolet?▼
B2960 stands for "Key/Immobilizer Communication Error." B2960 is a body/security code indicating a key or immobilizer (anti-theft) communication error, where the security module read sensor or key data that appears valid in form but does not match the expected, previously learned value. On many vehicles this involves a Passlock or transponder/immobilizer check that must pass before the computer allows the engine to start. When it fails, you typically get a security/anti-theft warning light and a no-start or no-crank condition. This is a manufacturer-specific code tied to the theft-deterrent system rather than an engine mechanical fault. On Chevrolet specifically, this code is documented across 5 models.
What causes B2960 on Chevrolet vehicles?▼
Common causes on Chevrolet: Faulty Passlock/ignition lock cylinder sensor, Damaged or worn transponder key or key chip, Wiring or connector fault in the security sensor circuit, Body control module (BCM) failure or needs relearn, Incomplete or lost immobilizer/key relearn procedure. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix B2960 on a Chevrolet?▼
Repair costs on Chevrolet range from $50 to $800, depending on the specific model and root cause.
Which Chevrolet models have B2960 documented?▼
Au7o has documented B2960 on 5 Chevrolet models: Cavalier, Colorado, HHR, Impala, Malibu.