AutoCodes – Generic – P16E4

P16E4 Code - Sensor Communication Circuit 3 Low Voltage

Quick Answer

The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to constantly adjust the high-pressure fuel pump's feed rate so that the ideal pressure is permanently maintained in the high-pressure section (between the high-pressure fuel pump and the injectors) by means of closed-loop control. Common causes include Low or no fuel, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure harness is open or shorted. 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: P16E4 indicates Sensor Communication Circuit 3 Low Voltage.
Common causes: Common causes include Low or no fuel, Faulty Fuel Rail Pressure (FRP) Sensor, Fuel Rail Pressure harness is open or shorted.
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 8,573

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 May 30, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P16E4 Description

The Engine Control Module (ECM) uses the Fuel Rail Pressure (FRP) sensor to constantly adjust the high-pressure fuel pump's feed rate so that the ideal pressure is permanently maintained in the high-pressure section (between the high-pressure fuel pump and the injectors) by means of closed-loop control. The fuel rail pressure sensor transmits fuel pressure and temperature information via serial data to the ECM. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low. The ECM controls the fuel pressure regulator, which regulates high-pressure fuel that goes to the fuel injector rails and the injectors. The Diagnostic Trouble Code (DTC) will be set if the Fuel Rail Pressure Sensor Signal is less than a predefined threshold for greater than 2.6 s.

OBDII Code P16E4 - Sensor Communication Circuit 3 Low Voltage - AutoCodes.com — P16E4 Code - Sensor Communication Circuit 3 Low Voltage

What does this mean?

What are the Possible Causes of the DTC P16E4?

Low or no fuel
Faulty Fuel Rail Pressure (FRP) Sensor
Fuel Rail Pressure harness is open or shorted
Fuel Rail Pressure circuit poor electrical connection
Faulty Fuel Pump

How to Fix the DTC P16E4?

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 P16E4 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 P16E4 code?

Need more information on how to fix the P16E4 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P16E4 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P16E4 Buick — Sensor Communication Circuit 3 Low Voltage
P16E4 Cadillac — Sensor Communication Circuit 3 Low Voltage
P16E4 Chevrolet — Sensor Communication Circuit 3 Low Voltage
P16E4 GMC — Sensor Communication Circuit 3 Low 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 P16E4 Code

1. What are the common symptoms of OBDII code P16E4 (Sensor Communication Circuit 3 Low Voltage)?

Symptoms may include poor engine performance, rough idling, decreased fuel efficiency, and an illuminated check engine light.

2. What are the possible causes of OBDII code P16E4?

Potential causes include a faulty sensor, damaged wiring or connectors in the communication circuit, a weak battery, or an issue with the vehicle's powertrain control module (PCM).

3. How can I diagnose the reason behind OBDII code P16E4?

Diagnosis typically involves using an OBDII scanner to read the code, inspecting the sensor and its connections, checking for damaged wiring, testing the battery voltage, and performing a scan tool test of the PCM.

4. Can I continue driving my vehicle with OBDII code P16E4 active?

It is generally not recommended to drive with this code active, as it can lead to further damage to the vehicle and potentially cause safety issues. It's best to address the underlying problem promptly.

5. How can I repair OBDII code P16E4 at home?

If you have the necessary tools and expertise, you may be able to replace the sensor, repair damaged wiring, or clean and secure connectors yourself. However, for more complex issues, it's advisable to seek professional help.

6. Is OBDII code P16E4 a serious issue that requires immediate attention?

While the severity of the issue can vary, it's important to address this code promptly to prevent any potential damage to the vehicle and ensure optimal performance.

7. Can a weak battery cause OBDII code P16E4 to trigger?

Yes, a weak or failing battery can lead to voltage fluctuations in the sensor communication circuit, triggering the P16E4 code. Make sure to check the battery's condition during diagnosis.

8. How much does it typically cost to repair OBDII code P16E4 at a mechanic or dealership?

Costs can vary depending on the exact cause of the issue, labor rates in your area, and the cost of parts. It's recommended to get a diagnostic and repair estimate from a trusted mechanic or dealership.

9. Are there any preventative measures I can take to avoid OBDII code P16E4 in the future?

Regular maintenance, such as checking and replacing sensors, inspecting wiring for damage, and ensuring a healthy battery, can help prevent issues that trigger the P16E4 code.

10. Can resetting the check engine light on my dashboard resolve OBDII code P16E4?

While clearing the code may temporarily turn off the check engine light, the underlying issue causing the P16E4 code will still exist. It's crucial to diagnose and address the root cause to prevent the code from reoccurring.