Decode Your Car Diagnostic Code
Free step-by-step OBD-II diagnostic trouble code guides for Powertrain, Body, Chassis & Network systems
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B1342
The B1342 code signals an internal hardware fault inside the Body Control Module (BCM). The module’s processor or memory can’t reliably control lights, door locks, and other comfort functions, so it shuts down to protect the vehicle.
B1600
The B1600 code indicates that the Passive Anti-Theft System (PATS) has received an incorrect key code, preventing the vehicle from starting. This code is typically triggered when the PATS system detects a mismatch between the expected and actual key code. The PATS system uses a transponder chip in the key to verify the key's authenticity and authorize the vehicle to start.
B2799
The B2799 code tells the vehicle’s control module that the immobilizer (anti‑theft) system is not communicating correctly. It usually means a key‑recognition problem, a wiring fault, or a faulty immobilizer control unit.
B1318
The B1318 code tells the vehicle’s body control module that the on‑board battery voltage is below the safe operating threshold. This usually means the battery, alternator, or wiring isn’t delivering enough voltage for the vehicle’s electrical accessories.
B1325
B1325 signals that the on‑board battery voltage is outside the calibrated range (too high or too low). The condition usually points to a weak battery, a slipping alternator belt, a failing alternator, or a defective voltage regulator.
B0100
The B0100 code signals a fault in the Electronic Frontal Sensor 1, the primary detector for frontal impacts that tells the airbag control module when to fire. Typical triggers are a damaged sensor, corroded wiring, or a loose connector.
B1000
The B1000 code signals that the air‑bag control unit (ECU) has detected an internal fault and cannot perform its safety functions. The error is stored as a permanent DTC.
C0561
The C0561 code tells the vehicle that the ABS control module has stored a ‘system disabled’ flag. This usually means a communication loss or a sensor fault that caused the ABS to turn off to protect the brakes.
C0035
The ABS control module is not receiving a valid signal from the left‑front wheel speed sensor. This usually points to a broken sensor, damaged wiring, or a connector problem, which stops the vehicle from correctly regulating brake force during hard stops.
C0040
The C0040 code Right Front Wheel Speed Sensor Circuit Malfunction tells the vehicle’s computer that the circuit for the right‑front wheel speed sensor is not providing a valid signal. This usually means the sensor, its wiring, or the tone ring is damaged, dirty, or disconnected, preventing the ABS from accurately measuring wheel speed.
C0045
The ABS control module is not receiving a valid signal from the left‑rear wheel speed sensor. Common causes are a broken wire, a dirty or failed sensor, or a loose connector.
C0050
The ABS control module is not receiving a valid signal from the rear‑right wheel speed sensor. The fault usually stems from a broken wire, a corroded connector, or a failed sensor, preventing the ABS from measuring wheel speed accurately.
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