P0118 – Engine Coolant Temperature Circuit High Input
Introduction
Let’s break down exactly what the P0118 trouble code means for your JAC and how to fix it.
The **P0118 error** is often linked to a faulty engine coolant temperature sensor or wiring issues, resulting in a **medium** severity level. The urgency of repair is **soon**, as driving with this code can lead to decreased engine performance and potential damage to the engine.
WHAT DOES CODE P0118 MEAN
The P0118 trouble code indicates a high input in the engine coolant temperature circuit, which may be associated with a malfunctioning engine coolant temperature sensor or wiring issues. This code affects the engine control module’s ability to accurately monitor engine temperature, potentially impacting engine performance, fuel efficiency, and emissions. The engine control module relies on this sensor to adjust fuel injection, ignition timing, and other parameters to optimize engine operation.
COMMON JAC MODELS AFFECTED
The P0118 code can affect various JAC models, including:
- JAC J5
- JAC J6
- JAC Refine M1
- JAC S3
- JAC S5
SYMPTOMS TABLE
The following symptoms may be experienced when the P0118 code is present:
| Symptom | Frequency of Occurrence |
|---|---|
| Decreased engine performance | High |
| Increased fuel consumption | Medium |
| Engine overheating | Low |
| Check Engine Light illumination | High |
| Difficulty starting the engine | Individual |
| Erratic engine idle | Medium |
| Reduced power output | High |
CAUSES TABLE
The following potential causes may be associated with the P0118 code:
| Potential Cause | Probability |
|---|---|
| Faulty engine coolant temperature sensor | High |
| Wiring issues or corrosion | Medium |
| Engine coolant temperature sensor circuit malfunction | Low |
| ECU software issues | Low |
| Engine mechanical problems (e.g., head gasket failure) | Medium |
REAL-WORLD DRIVING SCENARIOS
When driving with the P0118 code, the driver may experience decreased engine performance, particularly during cold starts or when accelerating from a standstill. The engine may also run rough or stall, and fuel consumption may increase. In some cases, the engine may overheat, leading to further damage.
DIAGNOSTIC STEPS
To diagnose the P0118 code, follow these steps:
1. Use a scan tool to monitor the engine coolant temperature sensor readings and compare them to the expected values.
2. Inspect the engine coolant temperature sensor and its wiring for signs of damage or corrosion.
3. Check the sensor’s resistance using a multimeter to verify its operation.
4. Perform a wiring check to ensure that the circuit is intact and not shorted to ground or power.
5. Consult the JAC service manual for specific diagnostic procedures and troubleshooting guides.
COMMON DIAGNOSTIC MISTAKES
Common mistakes when diagnosing the P0118 code include:
1. Failing to consult the service manual for specific diagnostic procedures.
2. Not inspecting the wiring and connections thoroughly.
3. Replacing the engine coolant temperature sensor without verifying its operation.
4. Not checking for other related trouble codes (e.g., P0125 or P0128).
5. Not performing a thorough visual inspection of the engine and its components.
WHEN NOT TO REPLACE THE SENSOR
Replacing the engine coolant temperature sensor may not solve the issue if:
1. The wiring or circuit is damaged or corroded.
2. The ECU has a software issue or is faulty.
3. There are vacuum leaks or other engine mechanical problems.
4. The cooling system is not functioning properly.
HOW TO FIX
To fix the P0118 code, follow these steps:
1. Inspect and repair or replace the engine coolant temperature sensor and its wiring as needed.
2. Consult the service manual for specific repair procedures.
3. Use a scan tool to clear the code and monitor the engine’s operation.
4. Perform a test drive to verify that the issue is resolved.
SEVERITY LEVEL
The P0118 code has a **medium** severity level, as it can lead to decreased engine performance, increased fuel consumption, and potential engine damage if left unrepaired. The urgency of repair is **soon**, as driving with this code can exacerbate the issue.
IS IT SAFE TO DRIVE WITH THIS CODE
It is not recommended to drive with the P0118 code for an extended period, as it can lead to decreased engine performance, increased fuel consumption, and potential engine damage. However, in some cases, it may be safe to drive for a short distance to a repair shop.
ESTIMATED REPAIR COST
The estimated repair cost for the P0118 code can range from $50 to $500, depending on the specific cause and the labor costs of the repair shop.
PREVENTIVE MAINTENANCE TIPS
To prevent the P0118 code from occurring, regular maintenance is recommended, including:
1. Checking the engine coolant level and condition.
2. Inspecting the engine coolant temperature sensor and its wiring.
3. Monitoring the engine’s temperature and performance.
When diagnosing the P0118 code, it is essential to consult the JAC service manual for specific procedures and troubleshooting guides. Additionally, using a scan tool to monitor the engine’s operation and performing a thorough visual inspection can help identify the root cause of the issue.
TOOLS REQUIRED FOR DIAGNOSTICS
The following tools are required for diagnosing the P0118 code:
- Scan tool
- Multimeter
- Wiring diagram
- Service manual
TECHNICAL REFERENCE VALUES
The following technical reference values are relevant for diagnosing the P0118 code:
| Parameter | Normal Range | Fault Indication Behavior |
|---|---|---|
| Engine coolant temperature | 150°F – 200°F | High or low readings |
| Engine coolant temperature sensor resistance | 1000 ohms – 5000 ohms | Out-of-range readings |
18. FAQ
1. What does code P0118 mean?
The P0118 error code indicates a high input in the engine coolant temperature circuit, which may be associated with a faulty engine coolant temperature sensor or wiring issues. This code affects the engine control module’s ability to accurately monitor engine temperature, potentially impacting engine performance, fuel efficiency, and emissions.
2. Is it safe to drive with code P0118?
It is not recommended to drive with the P0118 code for an extended period, as it can lead to decreased engine performance, increased fuel consumption, and potential engine damage. However, in some cases, it may be safe to drive for a short distance to a repair shop.
3. Will the code clear itself?
The P0118 code will not clear itself and requires diagnosis and repair to resolve the issue. The code may be cleared using a scan tool, but it will return if the underlying cause is not addressed.
4. Does the sensor need replacement?
The engine coolant temperature sensor may need replacement if it is faulty or damaged. However, it is essential to diagnose the issue thoroughly to determine the root cause of the P0118 code.
5. How much does it cost to fix?
The estimated repair cost for the P0118 code can range from $50 to $500, depending on the specific cause and the labor costs of the repair shop. The cost of replacing the engine coolant temperature sensor can range from $20 to $100, depending on the quality and brand of the sensor.
RELATED TROUBLE CODES
The following trouble codes are related to the P0118 code:
- Error P0125 on JAC — faulty engine coolant temperature sensor
- Error P0128 on JAC — engine coolant temperature sensor circuit malfunction
- Error P0130 on JAC — faulty oxygen sensor
- Error P0141 on JAC — faulty oxygen sensor heater circuit