AutoCodes – Buick – P1478 Buick

P1478 Buick Code - Particulate Matter Sensor Temperature Circuit High Voltage

Quick Answer

The Particulate Matter (PM) sensor monitors the amount of the particulates (soot) in the diesel exhaust gas exiting the tailpipe. Common causes include Faulty Exhaust Particulate Matter Sensor, Exhaust Particulate Matter Sensor harness is open or shorted, Exhaust Particulate Matter Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1478 Buick indicates Particulate Matter Sensor Temperature Circuit High Voltage.
Common causes: Common causes include Faulty Exhaust Particulate Matter Sensor, Exhaust Particulate Matter Sensor harness is open or shorted, Exhaust Particulate Matter Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 446

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 30, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1478 Buick Description

The Particulate Matter (PM) sensor monitors the amount of the particulates (soot) in the diesel exhaust gas exiting the tailpipe. The PM sensor is similar to the heated oxygen sensor with a ceramic element but also includes an individually calibrated Sensor Control Unit (SCU). The sensing element includes comb-shaped Interdigital Electrodes (IDE), a heater and a positive temperature coefficient resistor for temperature measurement.
The operation of the PM Sensor is based on the electrical conductivity characteristic of the diesel particulate. As the exhaust gas flows over the sensing element, soot is absorbed in the combs between the electrodes, eventually creating a conductive path. When the path is formed, it generates a current based on the voltage being applied to the element. The measurement process continues until a preset current value is reached. To avoid misleading readings, the sensor performs a regeneration where the soot is cleaned off by heating up the element before the measurement phase begins. The amount of regenerations is based on vehicle strategy; when the calibrated number of regenerations is reached, the cumulative current readings are used to determine the amount of soot concentration in the exhaust gas which in turn determines the collection efficiency of the Diesel Particulate Filter (DPF).
The Diagnostic Trouble Code (DTC) will be set when the particular matter sensor control unit detects a fault in the particulate matter sensor circuitry.

OBDII Code P1478 Buick - Particulate Matter Sensor Temperature Circuit High Voltage - AutoCodes.com — P1478 Buick Code - Particulate Matter Sensor Temperature Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1478 Buick?

Faulty Exhaust Particulate Matter Sensor
Exhaust Particulate Matter Sensor harness is open or shorted
Exhaust Particulate Matter Sensor circuit poor electrical connection

How to Fix the DTC P1478 Buick?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1478 Buick code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Need Help with the Code?

Get the P1478 Buick code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1478 Buick Code

1. What are the common symptoms of OBDII code P1478 in a Buick related to the Particulate Matter Sensor Temperature Circuit High Voltage issue?

The common symptoms include the Check Engine Light illuminating, reduced engine performance, increased fuel consumption, and potential black smoke from the exhaust.

2. What are the possible causes of OBDII code P1478 in a Buick indicating a Particulate Matter Sensor Temperature Circuit High Voltage problem?

Possible causes may include a faulty particulate matter sensor, damaged wiring or connectors in the sensor circuit, a defective powertrain control module (PCM), or issues with the exhaust system.

3. How can I diagnose the OBDII code P1478 in my Buick related to the Particulate Matter Sensor Temperature Circuit High Voltage fault?

Diagnosis typically involves using an OBDII scanner to retrieve the code, inspecting the particulate matter sensor and its connections, checking for damaged wiring, and testing the sensor's resistance and voltage.

4. Is it safe to continue driving my Buick with the OBDII code P1478 indicating a Particulate Matter Sensor Temperature Circuit High Voltage malfunction?

It is not recommended to drive the vehicle for an extended period with this issue, as it can result in decreased fuel efficiency and potential damage to the engine or emissions system.

5. Can I reset the OBDII code P1478 in my Buick without fixing the underlying Particulate Matter Sensor Temperature Circuit High Voltage problem?

While you can clear the code with an OBDII scanner, it is crucial to address the root cause of the issue to prevent further damage and ensure proper vehicle operation.

6. What are some repair tips for resolving OBDII code P1478 in a Buick related to the Particulate Matter Sensor Temperature Circuit High Voltage trouble code?

Repair tips may include checking and repairing any damaged wiring or connectors, replacing the faulty particulate matter sensor, and ensuring proper connection and functioning of the sensor.

7. How much does it typically cost to repair OBDII code P1478 in a Buick due to the Particulate Matter Sensor Temperature Circuit High Voltage issue?

The cost of repairs can vary depending on the specific cause of the problem and the labor rates in your area. Replacing the particulate matter sensor or repairing wiring issues could range from $200 to $500 or more.

8. Can a DIY enthusiast fix the OBDII code P1478 in a Buick related to the Particulate Matter Sensor Temperature Circuit High Voltage problem?

While some aspects of the repair, such as checking connections and replacing the sensor, can be done by a DIY enthusiast, it is recommended to consult a professional mechanic for accurate diagnosis and proper repair.

9. How often does the OBDII code P1478 occur in Buick vehicles due to the Particulate Matter Sensor Temperature Circuit High Voltage issue?

The occurrence of this specific code can vary among Buick models, but it is relatively rare compared to other common OBDII trouble codes.

10. Are there any recalls or technical service bulletins (TSBs) related to OBDII code P1478 in Buick vehicles with the Particulate Matter Sensor Temperature Circuit High Voltage problem?

It is advisable to check with Buick dealerships or online databases for any relevant recalls or TSBs addressing the Particulate Matter Sensor Temperature Circuit High Voltage issue and OBDII code P1478 in your specific Buick model.