P0435 indicates a malfunction in the catalyst temperature sensor circuit for Bank 2, Sensor 1. This sensor monitors the temperature of the catalytic converter to protect it from overheating and to aid in emissions control. The code sets when the PCM detects a voltage or resistance reading outside the expected range.
The sensor itself is the most common failure point. Internal short, open circuit, or degraded thermistor element can cause incorrect readings.
Wiring harness chafing, broken wires, or corrosion at the sensor connector can interrupt the signal or cause high resistance.
An exhaust leak upstream of the sensor can alter the temperature profile, causing the PCM to see an unexpected reading.
Oil, coolant, or debris on the sensor tip can insulate it and produce inaccurate temperature readings.
Extremely rare. Only consider after thoroughly checking all wiring, connectors, and the sensor itself. A PCM fault would likely affect multiple circuits.
Yes, in most cases the vehicle remains drivable. However, the catalyst temperature monitoring is disabled, which could lead to undetected overheating and potential converter damage over time. It's best to diagnose and repair the issue promptly.
No. P0435 is a circuit fault for the temperature sensor, not a catalyst efficiency code. Replacing the converter will not address a wiring or sensor problem. The sensor itself or its circuit is the likely cause.
No. The PCM is rarely the cause. Many drivers are incorrectly told to replace the PCM, but that is usually wrong. Always inspect the sensor, wiring, and connector first. A PCM failure would typically cause multiple unrelated codes.