Your 2021 Sorento stalls specifically when you shift into reverse—a frustrating and potentially dangerous situation in parking lots and driveways. The P0340 camshaft position sensor code provides a starting point for diagnosis.
Why Stalling in Reverse?
Shifting into reverse loads the engine differently than Drive. The torque converter applies load immediately, and if the engine is already struggling to maintain idle, this additional load causes a stall. The camshaft position sensor issue may be causing:
- Incorrect fuel injection timing
- Improper spark timing
- Rough idle that can't handle the load
What P0340 Indicates
The P0340 code means "Camshaft Position Sensor Circuit Malfunction (Bank 1)." This sensor tells the engine computer exactly where the camshaft is in its rotation—critical information for fuel injection and spark timing.
Symptoms You're Experiencing
- Engine stalls when shifting to Reverse
- May also stall shifting into Drive
- Rough or unstable idle
- Check engine light illuminated
- Possible hard starting
Common Causes
- Failed CMP sensor - Sensor providing erratic or no signal
- Wiring damage - Broken or corroded wires to sensor
- Connector issue - Loose or contaminated connection
- Timing chain stretch - Creates out-of-range readings
- Oil contamination - Oil soaking the sensor or connector
Diagnostic Steps
- Check CMP sensor connector for corrosion or loose fit
- Inspect wiring for damage or oil contamination
- Test sensor resistance with multimeter
- Monitor sensor signal with scan tool during operation
- Check for timing chain noise or related codes
Repair Costs
- CMP sensor: $100-$300
- Wiring repair: $100-$250
- Connector repair: $50-$150
- Timing chain service: $800-$2,000 (if related)