P1118 2004 Toyota Prius Code - Coolant Temperature Sensor Circuit High for Coolant Heat Storage System
Quick Answer
This system uses an electric pump to supply hot coolant stored in the coolant heat storage tank into the cylinder head of the engine, in order to optimize engine starting combustion and reduce the amount of unburned gas that is discharged while the engine is started. Common causes include Coolant Heat Storage Tank, Faulty Engine Coolant Temperature (ECT) sensor for CHS (Coolant Heat Storage), Low engine coolant level. 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
- P1118 2004 Toyota Prius indicates Coolant Temperature Sensor Circuit High for Coolant Heat Storage System.
- Common causes
- Common causes include Coolant Heat Storage Tank, Faulty Engine Coolant Temperature (ECT) sensor for CHS (Coolant Heat Storage), Low engine coolant level.
- 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.
Code P1118 2004 Toyota Prius Description
What are the Possible Causes of the DTC P1118 2004 Toyota Prius?
- Coolant Heat Storage Tank
- Faulty Engine Coolant Temperature (ECT) sensor for CHS (Coolant Heat Storage)
- Low engine coolant level
- Engine Coolant Temperature (ECT) sensor for HST harness is open or shorted
- Engine Coolant Temperature (ECT) sensor for HST electrical circuit poor connection
- Faulty engine coolant thermostat
How to Fix the DTC P1118 2004 Toyota Prius?
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 P1118 2004 Toyota Prius 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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Frequently Asked Questions about P1118 2004 Toyota Prius Code
1. What does the OBDII code P1118 mean on a 2004 Toyota Prius?
P1118 indicates a problem with the coolant temperature sensor circuit for the Coolant Heat Storage (CHS) system, specifically a high voltage condition.
2. What are the symptoms of code P1118 in a 2004 Toyota Prius?
Common symptoms include the check engine light turning on, the hybrid system not operating optimally, and potential issues with engine warm-up or fuel efficiency.
3. What causes the P1118 code to appear on a Toyota Prius?
The primary causes include a faulty coolant temperature sensor, damaged wiring or connectors in the sensor circuit, or a malfunctioning Engine Control Module (ECM).
4. How do I diagnose the P1118 code on my Prius?
Start by checking the wiring and connectors for damage, corrosion, or loose connections. Use a multimeter to test the coolant temperature sensor’s resistance and inspect the ECM for proper function.
5. Can I drive my Prius with the P1118 code present?
While the car may still run, driving with this code can result in reduced fuel efficiency and improper hybrid system operation. It’s best to address the issue promptly.
6. How do I fix the P1118 code on a Toyota Prius?
Repairs may include replacing the coolant temperature sensor, repairing or replacing damaged wiring/connectors, or, in rare cases, addressing issues with the ECM.
7. Where is the coolant temperature sensor for the CHS system located in a 2004 Prius?
The sensor is located near the Coolant Heat Storage tank, typically mounted on or near the associated piping.
8. How much does it cost to fix a P1118 code on a Prius?
Costs vary depending on the issue. Replacing the coolant temperature sensor can cost $100–$300, while wiring repairs may vary based on labor rates.
9. Can a bad thermostat cause the P1118 code?
No, a bad thermostat is unlikely to trigger P1118, as this code specifically relates to the coolant temperature sensor circuit in the CHS system.
10. Is the P1118 code related to engine overheating?
Not directly. This code pertains to the Coolant Heat Storage system’s sensor circuit, but neglecting the issue could indirectly affect engine temperature regulation over time.
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