P0429 Code: Catalyst Heater Control Circuit (Bank 1)

Catalytic converters are one of the most significant emission add-ons ever installed on a vehicle. They reduce tailpipe emissions of carbon monoxide (CO) and hydrocarbons (HC).  However, they could develop issues over time. P0429 is one of the trouble codes related to a fault in the catalyst heater control circuit.

What Does the P0429 Code Mean?

Diagnostic trouble code (DTC) P0429 stands for “Catalyst Heater Control Circuit Bank 1.” The powertrain control module (PCM) sets it when it detects an issue with the catalytic converter’s heating element.

A catalytic converter uses a catalyst to create a chemical reaction that converts harmful exhaust emissions into less harmful substances. These catalysts are usually made up of rhodium, palladium, or platinum. These elements plus the extreme heat of the engine exhaust make the conversion of harmful substances possible.

The PCM logs code P0429 when the exhaust oxygen concentration measured by the upstream and downstream oxygen (O2) sensors is comparable. It could also store the code if it detects an electrical issue with the heated catalyst control circuit.

Note: The definition of code P0429 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P0429 Code?

• Bad exhaust temperature sensor
• Damaged wirings and/or connectors
• Bad O2 sensors
• Malfunctioning catalytic converter
• Engine exhaust leak

What are the Common Symptoms of the P0429 Code?

• Poor fuel economy
• Illuminated check engine light

How to Diagnose the P0429 Code

DTC P0429 is a generic trouble code, but that does not imply that it has a universal solution. The steps for diagnosing this trouble code might differ depending on the vehicle.

In most cases, you’ll need more than a scan tool to diagnose a P0429 code. You’ll need specific equipment as well as up-to-date technical information about your vehicle’s traction control system. So if you are unfamiliar with vehicle repair and diagnosis, it is best to leave it to a reputable mechanic.

How to Fix the P0429 Code

Attempting to resolve any trouble code can be difficult, and the P0429 code is no exception. If you don’t have the necessary DIY skills and automotive know-how, it’s best to leave the job to a mechanic. Otherwise, you might end up causing more problems with your traction system.

However,  if you’re an experienced automotive DIYer and you want to do the job yourself, we recommend looking for vehicle-specific information before starting. Guides like those from Chilton or an ALLDATA subscription are helpful.

Get Replacement Sensors that Fit Your Vehicle

You can probably blame either a bad exhaust temperature sensor or a bad oxygen sensor for triggering the P0429 in your vehicle. If either of these sensors is on the fritz, they’re likely also behind any reduced fuel economy you’ve been noticing. Replace these faulty sensors right away if you don’t want to spend a fortune on fuel. Fortunately, you can easily purchase replacement sensors at CarParts.com.

CarParts.com knows how hard it can be to find the right sensors for your vehicle. With all the different makes and models out there, it can be tough to find sensors that fit. Thankfully, our easy-to-navigate site has a built-in vehicle selector tool. Once you put in your vehicle’s year, make, and model, you’ll see only parts that are guaranteed to fit your vehicle perfectly. There’s no need for guesswork after that. Simply pick the parts you need and proceed through our safe and convenient checkout.

Get your vehicle back on the road. Buy a new exhaust temperature sensor or other replacement sensors at CarParts.com today.