AutoCodes – Scion – P0128 2005 Scion xB

P0128 2005 Scion xB Code - Coolant Thermostat

Quick Answer

The thermostat is a component that blocks the flow of coolant to the radiator until the engine has warmed up. Common causes include Leaking or stuck open thermostat, Low engine coolant level, Insufficient warm up time. 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: P0128 2005 Scion xB indicates Coolant Thermostat.
Common causes: Common causes include Leaking or stuck open thermostat, Low engine coolant level, Insufficient warm up time.
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 7,637

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 21, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0128 2005 Scion xB Description

The thermostat is a component that blocks the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the engine. Once the engine reaches its operating temperature, the thermostat opens. The OBDII sets when the engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough. This is due to a leak in the seal or the thermostat open stuck.

OBDII Code P0128 2005 Scion xB - Coolant Thermostat - AutoCodes.com — P0128 2005 Scion xB Code - Coolant Thermostat

What does this mean?

What are the Possible Causes of the DTC P0128 2005 Scion xB?

Leaking or stuck open thermostat
Low engine coolant level
Insufficient warm up time
Faulty engine coolant temperature sensor
Engine coolant temperature sensor harness is open or shorted
Engine coolant temperature sensor circuit poor electrical connection

How to Fix the DTC P0128 2005 Scion xB?

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

If cooling system is not leaking and the fluid level is OK, replacing the thermostat usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0128 2005 Scion xB 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 P0128 2005 Scion xB Code

1. What does OBDII code P0128 mean for a 2005 Scion xB?

The P0128 code on a 2005 Scion xB indicates that the engine coolant temperature is below the thermostat regulating temperature.

2. What are the common symptoms of a P0128 code in a 2005 Scion xB?

Common symptoms of a P0128 code in a 2005 Scion xB include below-normal engine temperature, poor fuel economy, and possibly a check engine light.

3. What are the possible causes of a P0128 code in a 2005 Scion xB?

Possible causes of a P0128 code in a 2005 Scion xB include a faulty thermostat, low coolant level, a malfunctioning coolant temperature sensor, or a stuck-open thermostat.

4. How can I diagnose a P0128 code in my 2005 Scion xB?

To diagnose a P0128 code in a 2005 Scion xB, you can start by checking the coolant level, inspecting the thermostat for proper operation, and testing the coolant temperature sensor.

5. Can I continue driving my 2005 Scion xB with a P0128 code?

It is not recommended to continue driving your 2005 Scion xB with a P0128 code, as it can lead to poor engine performance and potential damage if not addressed promptly.

6. How do I repair a P0128 code in my 2005 Scion xB?

To repair a P0128 code in a 2005 Scion xB, you may need to replace the thermostat, address any coolant leaks, or replace the coolant temperature sensor as needed.

7. Are there any DIY tips for fixing a P0128 code in a 2005 Scion xB?

While some aspects of diagnosing and repairing a P0128 code may be DIY-friendly, it is recommended to consult a professional mechanic for an accurate diagnosis and proper repair.

8. How much does it cost to fix a P0128 code in a 2005 Scion xB?

The cost of fixing a P0128 code in a 2005 Scion xB can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor.

9. Will resetting the check engine light resolve a P0128 code in a 2005 Scion xB?

Simply resetting the check engine light will not fix the underlying issue causing the P0128 code in a 2005 Scion xB. It is important to diagnose and address the root cause of the problem.

10. How often does a P0128 code occur in a 2005 Scion xB?

A P0128 code can occur in a 2005 Scion xB due to various reasons, but it is not considered a common issue as long as the cooling system is properly maintained and monitored.