AutoCodes – Toyota – P1631 Toyota

P1631 Toyota Code - Communication Error from ECM to VSC

Quick Answer

The Engine Control Module (ECM) sends signals such as A/T information signals, dynamic radar cruise control operation signals, and brake operation demand signals to the Skid Control Electronic Control Unit (ECU) (Brake Actuator Assembly) when the dynamic radar cruise control is operating. Common causes include Faulty Skid Control ECU (Brake Actuator Assembly), Skid Control ECU harness is open or shorted, Skid Control ECU 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: P1631 Toyota indicates Communication Error from ECM to VSC.
Common causes: Common causes include Faulty Skid Control ECU (Brake Actuator Assembly), Skid Control ECU harness is open or shorted, Skid Control ECU 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 4,292

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 Mar 28, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1631 Toyota Description

The Engine Control Module (ECM) sends signals such as A/T information signals, dynamic radar cruise control operation signals, and brake operation demand signals to the Skid Control Electronic Control Unit (ECU) (Brake Actuator Assembly) when the dynamic radar cruise control is operating. The ECM is the only component that has a function to store and output Diagnostic Trouble Codes (DTC)s in the dynamic radar cruise control system. Therefore, if the Skid Control ECU (Brake Actuator Assembly) detects a communication error from the ECM, it sends a malfunction signal back to the ECM.
While the vehicle speed is 40 km/h (25 mph) or more and the dynamic radar cruise control system is operating (vehicle-to-vehicle distance control mode), if the ECM continuously receives a logical error signal from the skid control ECU (brake actuator assembly) for approximately 1 second or more the Diagnostic Trouble Code (DTC) will be set.

OBDII Code P1631 Toyota - Communication Error from ECM to VSC - AutoCodes.com — P1631 Toyota Code - Communication Error from ECM to VSC

What does this mean?

What are the Possible Causes of the DTC P1631 Toyota?

Faulty Skid Control ECU (Brake Actuator Assembly)
Skid Control ECU harness is open or shorted
Skid Control ECU circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P1631 Toyota?

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 P1631 Toyota 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 P1631 Toyota code?

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Information for Specific Toyota Models

P1631 2013 Toyota RAV4 — Communication Error from ECM to VSC
P1631 2014 Toyota RAV4 — Communication Error from ECM to VSC
P1631 2015 Toyota RAV4 — Communication Error from ECM to VSC
P1631 2016 Toyota RAV4 — Communication Error from ECM to VSC
P1631 2017 Toyota RAV4 — Communication Error from ECM to VSC
P1631 2018 Toyota RAV4 — Communication Error from ECM to VSC

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 P1631 Toyota Code

No Frequently Asked Questions about P1631 Toyota Code found.

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