Error Code P0197: What It Means & What To Do?

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Although this is a very serious error, but is also as difficult to detect as the only indication before any real damage happens is the Check Engine Light illuminated on the dashboard. However, this code needs to be addressed at early as possible it gets detected by the PCM. So, resolve this issue very carefully to avoid severe engine damages.

OBD-II Code Powertrain Control Module (PCM) failure is defined as an Engine Oil Temperature Sensor Circuit Low

Without engine oil there will be no lubrication of hundreds of moving metal parts, some of them separated by less than the width of a human hair, and the vehicle engine can quickly overheat and weld itself into a useless chunk of metal.

The PCM detects the engine oil temperature using the Engine Oil Temperature Sensor. The sensor functions to modify the voltage signal from the Engine Control Module (ECM). The modified signal is returned to the ECM as the engine oil temperature input. The sensor makes use of a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases and vice versa. When the PCM detects an anomaly in the EOT sensor voltage signal, P0197 is stored in the memory.

What causes the problem of Engine Oil temperature Sensor Low?

• Faulty/damaged Engine Oil Temperature sensor
• Engine Oil Temperature sensor harness open, shorted or damaged
• Engine Oil Temperature sensor circuit poor electrical connection

1. Engine Control Module - ECM faults can store and display wrong OBD Code which can result in wrong diagnosis. Thus, replace the damaged components now.
2. Powertrain Control Module - PCM issues directly affects the engine control and transmission control module. Thus, replace faulty components now.
3. Engine Oil Temperature Sensor - The sensor can be faulty if it doesn’t send the correct voltage signal to the PCM and might need replacement.
4. Thermistor - If you have a faulty thermistor, replace it immediately as the sensor will not be able to function properly.
5. Oil Temperature Gauge - A faulty gauge can transmit the wrong reading despite the sensor being working properly. Buy new gauges now!
6. Diagnostic Tool - Find wide range of diagnostic tools to detect and correct the OBD code error.

Typical symptoms of code P0197 are much the same across all applications, although the severity of one or more symptoms may vary between applications. If the Engine Control Unit detects low voltage from the EOT sensor, it will immediately flash Check Engine Light on the dashboard. In rare cases, the car may also run poorly and see increased fuel consumption.

Proper scan tools should be used to detect and diagnose the problems related to a particular OBD error code. After testing it is important to check that the error doesn’t reflect back anymore. Some of the common components that account to the major problems of the P0197 error code and when fixed can fix the problem are:

• Replacing the EOT sensor
• Repairing any damaged wiring in the EOT circuit
• Repairing damage or worn sensor connectors
• PCM repair or replacement 

At Parts Avatar Canada, find the best quality replacement and performance parts at the best price in the market to correctly diagnose the OBD Code P0197 error.

With the help of a professional mechanic, inspect all the components related to this error and follow the step by step diagnosis and carefully analyse the situation to diagnose this problem.

• Install a scan tool in vehicles OBD-II port to check if P0197 is present or not.
• Freeze frame data and test drive to check if the code reappears under same conditions.
• If the Check Engine Light returns upon test, then the code is confirmed.
• Performs a visual inspection of wiring and Engine Oil Temperature sensor for any damage, breaks, or shorted wiring.
• Check for the voltage of EOT sensor and make sure it is not excessively low. If low voltage is confirmed, EOT sensor is faulty.
• A diagnostic of the ECU will be performed, if the voltage is not low and sensors are fine.

Common Mistakes When Diagnosing The P0197 Code

P0197 is an uncommon code and following all diagnostic steps is important so nothing is overlooked. EOT sensors should be properly examined and replaced, if faulty. Always confirm low voltage for the sensor before any replacement is performed and avoid going to the ECU straightaway. Also check for the wiring and connectors in association with the sensor and the circuit.

• Not examining for blown fuses
• Replacing the sensor without examining the electricals and connectors
• Replacing the oxygen sensor without measuring resistance and voltage