AutoCodes – Lexus – P1438 Lexus

P1438 Lexus Code - HCAC System Variable Valve Circuit Low

Quick Answer

The Engine Control Module (ECM) monitors the Exhaust Gas Temperature Sensor. Common causes include Faulty HCAC VSV, HCAC VSV harness is open or shorted, HCAC VSV 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: P1438 Lexus indicates HCAC System Variable Valve Circuit Low.
Common causes: Common causes include Faulty HCAC VSV, HCAC VSV harness is open or shorted, HCAC VSV 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 3,423

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 21, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1438 Lexus Description

The Engine Control Module (ECM) monitors the Exhaust Gas Temperature Sensor. The ECM sets the Diagnostic Trouble Code (DTC) when the Exhaust Gas Temperature Sensor is not to factory specifications. HCAC (Hydro-Carbon Absorber and Catalyst System) fault detected.

OBDII Code P1438 Lexus - HCAC System Variable Valve Circuit Low - AutoCodes.com — P1438 Lexus Code - HCAC System Variable Valve Circuit Low

What does this mean?

What are the Possible Causes of the DTC P1438 Lexus?

Faulty HCAC VSV
HCAC VSV harness is open or shorted
HCAC VSV circuit poor electrical connection

How to Fix the DTC P1438 Lexus?

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 P1438 Lexus 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 P1438 Lexus code?

Need more information on how to fix the P1438 Lexus code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1438 Lexus code diagnosed by a professional: Find a repair shop in your area

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 P1438 Lexus Code

1. What are the common symptoms of OBDII code P1438 in a Lexus related to the HCAC System Variable Valve Circuit Low?

- Common symptoms may include rough idling, decreased engine performance, and potential stalling.

2. What are the possible causes of the P1438 code indicating a HCAC System Variable Valve Circuit Low in a Lexus?

- The code may be triggered by issues such as a faulty variable valve timing (VVT) control solenoid, wiring problems, or a malfunctioning VVT system.

3. How can I diagnose the P1438 code for the HCAC System Variable Valve Circuit Low in my Lexus?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, inspecting the VVT control solenoid and related wiring, and performing tests to determine the root cause.

4. Can a dirty engine oil or low oil level contribute to the P1438 code in a Lexus's HCAC System Variable Valve Circuit Low?

- Yes, inadequate or dirty engine oil can affect the proper functioning of the VVT system, potentially leading to the P1438 code being triggered.

5. What are some recommended repair tips for addressing the P1438 code related to the HCAC System Variable Valve Circuit Low in a Lexus?

- Repair tips may include replacing the VVT control solenoid, repairing any damaged wiring, ensuring proper engine oil levels, and clearing the code to see if it reoccurs.

6. Is it safe to continue driving my Lexus with the P1438 code for the HCAC System Variable Valve Circuit Low illuminated?

- It is generally not recommended to continue driving with this code active, as it can lead to further engine issues and potential damage if left unresolved.

7. How much can I expect to pay for repairs related to the P1438 code indicating HCAC System Variable Valve Circuit Low in a Lexus?

- Repair costs can vary depending on the exact cause of the issue, but they may range from a few hundred to over a thousand dollars, including parts and labor.

8. Can resetting the OBDII system clear the P1438 code for the HCAC System Variable Valve Circuit Low in a Lexus?

- Resetting the system may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear after driving cycles.

9. Are there any recalls or technical service bulletins related to the P1438 code for the HCAC System Variable Valve Circuit Low in Lexus vehicles?

- It's recommended to check with a Lexus dealership or online resources for any existing recalls or technical service bulletins related to this specific OBDII code.

10. How important is it to address the P1438 code indicating HCAC System Variable Valve Circuit Low in a timely manner?

- It's crucial to address the code promptly to prevent potential engine damage, ensure optimal vehicle performance, and maintain overall safety while driving.