AutoCodes – Generic – P2042

P2042 Code - Reductant Temperature Sensor Circuit

Quick Answer

The reductant heater and sender assembly contains pickup tube for reductant pump module, an electric heating element, a reductant temperature sensor and an electrode type level sensor. Common causes include Faulty Reductant Temperature Sensor, Reductant Temperature Sensor harness is open or shorted, Reductant Temperature 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: P2042 indicates Reductant Temperature Sensor Circuit.
Common causes: Common causes include Faulty Reductant Temperature Sensor, Reductant Temperature Sensor harness is open or shorted, Reductant Temperature 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 13,878

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 Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P2042 Description

The reductant heater and sender assembly contains pickup tube for reductant pump module, an electric heating element, a reductant temperature sensor and an electrode type level sensor. The heating element is directly above pickup tubes inlet filter. When reductant temperature sensor detects the diesel exhaust fluid temperature dropping to the freezing point of 12°F (-11°C), the PCM will command the glow plug control module to provide voltage to heating element. The heating element thaws liquid reductant within reductant heater and sender assembly reservoir during cold ambient temperatures.

OBDII Code P2042 - Reductant Temperature Sensor Circuit - AutoCodes.com — P2042 Code - Reductant Temperature Sensor Circuit

What does this mean?

What are the Possible Causes of the DTC P2042?

Faulty Reductant Temperature Sensor
Reductant Temperature Sensor harness is open or shorted
Reductant Temperature Sensor circuit poor electrical connection

How to Fix the DTC P2042?

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 P2042 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 P2042 code?

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Need Help with the Code?

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Information for Specific Makes

P2042 BMW — Reductant Temperature Sensor Circuit
P2042 Dodge — Reductant Temperature Sensor Circuit
P2042 Ford — Reductant Temperature Sensor Circuit

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.