AutoCodes – Chevrolet – P1478 Chevrolet

P1478 Chevrolet 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 Chevrolet 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 3,625

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

What does this mean?

What are the Possible Causes of the DTC P1478 Chevrolet?

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 Chevrolet?

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 Chevrolet 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.

Need more information about the P1478 Chevrolet code?

Need more information on how to fix the P1478 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

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

Information for Specific Chevrolet Models

P1478 2014 Chevrolet Silverado — Particulate Matter Sensor Temperature Circuit High Voltage
P1478 2015 Chevrolet Silverado — Particulate Matter Sensor Temperature Circuit High Voltage
P1478 2016 Chevrolet Silverado — Particulate Matter Sensor Temperature Circuit High Voltage
P1478 2017 Chevrolet Silverado — Particulate Matter Sensor Temperature Circuit High Voltage
P1478 2018 Chevrolet Silverado — Particulate Matter Sensor Temperature Circuit High Voltage

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 Chevrolet Code

1. What are the common symptoms of OBDII code P1478 in a Chevrolet vehicle?

The common symptoms of P1478 include decreased fuel efficiency, rough idling, lack of power, and potentially a Check Engine Light on the dashboard.

2. What does the OBDII code P1478 Chevrolet indicate?

P1478 indicates a high voltage condition in the particulate matter sensor temperature circuit of the Chevrolet vehicle.

3. What are the possible causes of OBDII code P1478 in a Chevrolet?

Possible causes of P1478 include a faulty particulate matter sensor, damaged wiring in the sensor circuit, or a malfunction in the sensor temperature circuit.

4. How can I diagnose the OBDII code P1478 in my Chevrolet?

Diagnosing P1478 typically involves using an OBDII scanner to retrieve the code, inspecting the particulate matter sensor and its wiring for any visible damage, and testing the sensor's voltage output.

5. Is it safe to continue driving with OBDII code P1478 in my Chevrolet?

It is not recommended to drive with an unresolved P1478 code, as it can lead to further damage to the vehicle's emissions control system and potentially affect engine performance.

6. Can I repair OBDII code P1478 in my Chevrolet by simply resetting the Check Engine Light?

Resetting the Check Engine Light may temporarily clear the code, but it is important to address the underlying issue causing P1478 to prevent the code from reoccurring.

7. How much does it typically cost to repair OBDII code P1478 in a Chevrolet?

The cost of repairing P1478 can vary depending on the specific cause of the code. It may involve replacing the particulate matter sensor, repairing damaged wiring, or addressing other related issues.

8. Are there any DIY tips for fixing OBDII code P1478 in a Chevrolet?

While some simple checks like inspecting the sensor and wiring can be done by DIY enthusiasts, diagnosing and repairing P1478 may require professional expertise and specialized tools.

9. Can a faulty particulate matter sensor cause other issues in a Chevrolet besides triggering code P1478?

Yes, a faulty particulate matter sensor can lead to decreased fuel efficiency, increased emissions, and potential damage to the vehicle's catalytic converter if left unresolved.

10. How often should the particulate matter sensor be inspected in a Chevrolet to prevent OBDII code P1478?

It is recommended to include the particulate matter sensor in regular maintenance checks to ensure its proper functioning and prevent issues like P1478 from occurring.