What does the Buick code 35 fault code mean?
3 Answers
Buick displays the fault code 35 due to excessive engine temperature. The main causes are as follows: 1. Insufficient engine coolant. 2. Water pump failure, drive belt wear or excessive looseness. 3. Thermostat main valve fails to open or opens too late. 4. Louvers cannot fully open. 5. Radiator fins are dirty, damaged, or radiator cooling tubes are clogged. 6. Fan clutch engages too late or cooling fan does not work, excessive fan rotation resistance, improper blade installation, blade damage, etc. Below are the meanings of common Buick fault codes: 1. code2: Key not detected, please press clutch to start; code3: Insufficient coolant, please add; code4: Engine overheated, AC turned off; code6: Press brake to release parking brake; code7: Turn steering wheel to start after stalling; code8: Repeat start after stalling; 2. code9: Turn steering wheel to restart; code10: Brake overheated; code11: Brake wear; code12: Vehicle overloaded; code15: High-mounted brake light failure; code16: Please check brake lights; code17: Headlight level adjustment failure.
The Buick code 35 is a fairly common fault, typically referring to the P0035 trouble code, which indicates an issue with the front oxygen sensor heater control circuit. I encounter this frequently during repairs, especially in older Buick models like the Regal or LaCrosse. The root cause could be a malfunctioning sensor heating circuit, aged or shorted wiring, or corroded/loose connectors, preventing the ECU from properly controlling the sensor heating. This triggers the check engine light, disrupts air-fuel ratio adjustment, and may cause sluggish acceleration, increased fuel consumption. If left unfixed long-term, it raises the risk of catalytic converter clogging. Upon detecting this code, don’t rush to replace parts—first inspect for oxidized/loose circuit connections and measure resistance/voltage to ensure they’re within specs. If simple fixes fail, the entire oxygen sensor needs replacement. I recall a recent case where an Excelle owner worsened the problem by DIY attempts, ultimately costing hundreds at the shop for proper repair. Regular maintenance like sensor cleaning can help prevent such issues.
It's really frustrating when the Buick engine light shows code 35, which usually indicates a P0035 error, meaning there's a circuit control issue with the oxygen sensor heating system. I was quite panicked when I first encountered this on my Cruze, as the car would experience unstable acceleration, poor throttle response, and idle shaking while driving. After checking online, I found it's mainly caused by water ingress and corrosion at the sensor connector or damaged wiring harness, sometimes it's just a minor ECU module issue. If left unattended for long, you might face penalties for excessive emissions or even engine damage. I later learned to avoid the sensor area when washing the car and regularly inspect and clean the engine bay wiring, but it's best to visit an auto repair shop for professional code diagnosis. The repair isn't expensive, and DIY enthusiasts might even replace the sensor themselves to save some money. Safety first though - don't risk driving safety over minor savings.
