AutoCodes – Volvo – P1238 Volvo

P1238 Volvo Code - Turbocharger Control valve

Quick Answer

The code O1238 will set if RPM is above 3500 and engine is operating at a high load, control signal to turbocharger control valve is at maximum and boos pressure from boos pressure sensor is lower than approximately 2.9 psi under normal boost pressure (signal too low. Common causes include Air leakage after turbocharger, Hoses between turbocharger and turbocharger control valve are loose, blocked or damage, Hoses between turbocharger control valve and pressure servo are loose, blocked or damage. 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: P1238 Volvo indicates Turbocharger Control valve.
Common causes: Common causes include Air leakage after turbocharger, Hoses between turbocharger and turbocharger control valve are loose, blocked or damage, Hoses between turbocharger control valve and pressure servo are loose, blocked or damage.
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 32,067

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 20, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P1238 Volvo Description

The code O1238 will set if RPM is above 3500 and engine is operating at a high load, control signal to turbocharger control valve is at maximum and boos pressure from boos pressure sensor is lower than approximately 2.9 psi under normal boost pressure (signal too low. If mass from mass air flow sensor is high than desired value (signal too high) it is interpreted as a fault by the Engine Control Module (ECM). When the code is set, a reduce boos pressure is used as a substitute value.

OBDII Code P1238 Volvo - Turbocharger Control valve - AutoCodes.com — P1238 Volvo Code - Turbocharger Control valve

What does this mean?

What are the Possible Causes of the DTC P1238 Volvo?

Air leakage after turbocharger
Hoses between turbocharger and turbocharger control valve are loose, blocked or damage
Hoses between turbocharger control valve and pressure servo are loose, blocked or damage
Faulty turbocharger control valve
Faulty boos pressure control valve pressure servo
Sticking boost pressure control valve

How to Fix the DTC P1238 Volvo?

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 does this mean?

Code Tech Notes

First step is checking for air leak after turbocharger.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1238 Volvo 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.

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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 P1238 Volvo Code

1. What are common symptoms of OBDII code P1238 in a Volvo related to the Turbocharger Control valve?

- Common symptoms include reduced engine power, poor acceleration, and potential stalling or rough idling.

2. What are the possible causes of OBDII code P1238 in a Volvo related to the Turbocharger Control valve?

- Possible causes include a faulty turbocharger control valve, wiring issues, vacuum leaks, or a malfunctioning turbocharger.

3. How can I diagnose the Turbocharger Control valve issue causing OBDII code P1238 in my Volvo?

- Diagnosis typically involves checking the turbocharger control valve for proper operation, inspecting the wiring and vacuum lines for damage, and performing a scan tool test.

4. Can a clogged or dirty turbocharger cause OBDII code P1238 in a Volvo?

- Yes, a clogged or dirty turbocharger can disrupt the proper operation of the turbocharger control valve, leading to the P1238 trouble code.

5. What are some repair tips for addressing OBDII code P1238 in a Volvo related to the Turbocharger Control valve?

- Repair tips may include cleaning or replacing the turbocharger control valve, repairing any damaged wiring or vacuum lines, and ensuring proper turbocharger function.

6. Is it safe to continue driving my Volvo with OBDII code P1238 related to the Turbocharger Control valve?

- It is not recommended to continue driving with this issue, as it can lead to further damage to the turbocharger and other engine components.

7. Can resetting the OBDII code P1238 in my Volvo make the issue go away temporarily?

- Resetting the code may temporarily clear the warning light, but if the underlying issue with the Turbocharger Control valve is not addressed, the code is likely to reappear.

8. How much does it typically cost to repair OBDII code P1238 in a Volvo related to the Turbocharger Control valve?

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

9. Are there any preventive maintenance steps I can take to avoid OBDII code P1238 in my Volvo related to the Turbocharger Control valve?

- Regularly inspecting and servicing the turbocharger system, including the control valve and associated components, can help prevent issues leading to the P1238 trouble code.

10. Can a DIY enthusiast with basic automotive skills repair OBDII code P1238 related to the Turbocharger Control valve in a Volvo?

- While some repairs may be possible for DIY enthusiasts, diagnosing and repairing issues with the turbocharger control valve often require specialized tools and expertise, so professional assistance is recommended.