AutoCodes – Generic – P1018

P1018 Code - Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage

Quick Answer

The Reductant Quality Sensor is located in the reductant tank and uses an ultrasonic signal to measure reductant fluid quality. Common causes include Faulty Reductant Control Module, Reductant Control Module harness is open or shorted, Reductant Control Module 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: P1018 indicates Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage.
Common causes: Common causes include Faulty Reductant Control Module, Reductant Control Module harness is open or shorted, Reductant Control Module 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 14,279

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 Jul 24, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P1018 Description

The Reductant Quality Sensor is located in the reductant tank and uses an ultrasonic signal to measure reductant fluid quality. The Reductant Quality Sensor includes an integrated temperature sensor to measure reductant fluid temperature. The Reductant Quality Sensor communicates with the Reductant Control Module using serial data. The Diagnostic Trouble Code (DTC) will be set if the reductant control module detects a short to ground on the 5 V reference circuit for greater than 1 s.

OBDII Code P1018 - Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage - AutoCodes.com — P1018 Code - Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1018?

Faulty Reductant Control Module
Reductant Control Module harness is open or shorted
Reductant Control Module circuit poor electrical connection
Faulty Reductant Quality Sensor

How to Fix the DTC P1018?

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 P1018 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 P1018 code?

Need more information on how to fix the P1018 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1018 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1018 Audi — Intake Manifold Runner Bank 2 Lower Limit Not Reached
P1018 Buick — Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage
P1018 Cadillac — Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage
P1018 Chevrolet — Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage
P1018 Dodge — MAP Circuit HighReductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage
P1018 GMC — Reductant Control Module Sensor Communication Voltage Supply Circuit Low Voltage
P1018 Volkswagen — Intake Manifold Runner Bank 2 Lower Limit Not Reached

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.