P0117 – OBD-II DTC

OBD-II DTC P0117 – Engine Coolant Temperature Circuit Low Input

DTC P0117 meaning

DTC P0117 refers to a diagnostic trouble code indicating a low input signal from the engine coolant temperature (ECT) sensor. The ECT sensor monitors the temperature of the engine coolant and sends this information to the engine control module (ECM). A low input signal suggests that the sensor is reporting a temperature that is lower than expected, which can lead to improper engine operation and performance issues.

DTC P0117 symptoms

Common symptoms associated with DTC P0117 may include:

• Check Engine Light illuminated
• Engine overheating or running too cold
• Poor fuel economy
• Rough engine idle
• Increased emissions

DTC P0117 causes

Several factors can trigger DTC P0117, including:

• Faulty engine coolant temperature sensor
• Wiring issues, such as short circuits or open circuits
• Corroded or loose electrical connections
• Faulty engine control module (ECM)
• Low coolant levels or coolant leaks

DTC P0117 seriousness

DTC P0117 can be serious as it affects engine performance and efficiency. If left unaddressed, it may lead to:

• Engine overheating
• Increased wear and tear on engine components
• Potential engine damage
• Failed emissions tests

How to diagnose DTC P0117

To diagnose DTC P0117, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the code.
2. Inspect the engine coolant temperature sensor and its wiring for damage or corrosion.
3. Check the coolant level and ensure it is within the recommended range.
4. Test the ECT sensor using a multimeter to verify its resistance at various temperatures.
5. Examine the ECM for any software updates or faults.

How to fix DTC P0117 step-by-step instructions

To fix DTC P0117, follow these steps:

1. Address any wiring issues by repairing or replacing damaged wires and connectors.
2. Replace the faulty engine coolant temperature sensor if testing indicates it is not functioning correctly.
3. Ensure the coolant level is adequate and repair any leaks if necessary.
4. Clear the DTC using an OBD-II scanner and test drive the vehicle to see if the code returns.
5. If the code reappears, further diagnose the ECM or consider professional assistance.

How to erase DTC P0117

To erase DTC P0117, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear Codes” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to ensure the code does not return.

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