Engine-CodesCadillac – P1187 Cadillac

P1187 Cadillac Code - Engine Oil Temperature Sensor Circuit Low Voltage

Quick Answer

The P1187 Cadillac code indicates that there is an issue with the Engine Oil Temperature Sensor Circuit, specifically that the voltage is reading lower than the specified range. Common causes include Faulty Engine Oil Temperature Sensor: The sensor itself may be malfunctioning and providing incorrect voltage readings, Wiring or Connector Issues: Damaged or corroded wiring or connectors in the sensor circuit can disrupt the voltage signal, Engine Control Module (ECM) Problems: Issues with the ECM, which processes sensor data, can also lead to low voltage readings. 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
P1187 Cadillac indicates Engine Oil Temperature Sensor Circuit Low Voltage.
Common causes
Common causes include Faulty Engine Oil Temperature Sensor: The sensor itself may be malfunctioning and providing incorrect voltage readings, Wiring or Connector Issues: Damaged or corroded wiring or connectors in the sensor circuit can disrupt the voltage signal, Engine Control Module (ECM) Problems: Issues with the ECM, which processes sensor data, can also lead to low voltage readings.
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.
Table of contents Created and updated by William Orellana on Sep 10, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P1187 Cadillac Description

The P1187 Cadillac code indicates that there is an issue with the Engine Oil Temperature Sensor Circuit, specifically that the voltage is reading lower than the specified range. This sensor is responsible for monitoring the temperature of the engine oil, which is crucial for maintaining proper engine performance and longevity. When the sensor detects low voltage, it can lead to inaccurate temperature readings, potentially causing the engine to run too hot or too cold. This can affect fuel efficiency, emissions, and overall engine health.

OBDII Code P1187 Cadillac - Engine Oil Temperature Sensor Circuit Low Voltage
P1187 Cadillac Code - Engine Oil Temperature Sensor Circuit Low Voltage

Common Causes of P1187 Cadillac

  1. Faulty Engine Oil Temperature Sensor: The sensor itself may be malfunctioning and providing incorrect voltage readings.
  2. Wiring or Connector Issues: Damaged or corroded wiring or connectors in the sensor circuit can disrupt the voltage signal.
  3. Engine Control Module (ECM) Problems: Issues with the ECM, which processes sensor data, can also lead to low voltage readings.
  4. Low Engine Oil Level: Insufficient engine oil can affect the temperature sensor's performance and cause low voltage readings.
  5. Environmental Factors: Extreme temperatures or exposure to moisture can also impact the sensor's functionality.

Symptoms of P1187 Cadillac

  1. Check Engine Light: The most common symptom associated with this code is the illumination of the check engine light on the vehicle's dashboard.
  2. Inaccurate Temperature Readings: The engine oil temperature gauge may show incorrect readings or fluctuate erratically.
  3. Engine Performance Issues: The vehicle may experience decreased performance, rough idling, or stalling due to the incorrect temperature readings.
  4. Poor Fuel Efficiency: A faulty engine oil temperature sensor can lead to poor fuel efficiency as the engine may not be operating at the optimal temperature.

How to Fix P1187 Cadillac

  1. Diagnostic Testing: Begin by using a diagnostic scanner to retrieve the specific trouble code and perform further testing to pinpoint the issue.
  2. Inspect Sensor and Wiring: Check the engine oil temperature sensor and its wiring for any visible damage or corrosion. Replace any faulty components.
  3. Test Voltage: Use a multimeter to test the voltage output of the sensor and ensure it is within the specified range.
  4. Check ECM: Inspect the engine control module for any signs of damage or malfunction. Reset the ECM if necessary or replace it if faulty.
  5. Clear Codes and Test Drive: After completing the repairs, clear the trouble codes from the vehicle's computer and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P1187 Cadillac

The typical repair costs for addressing the P1187 Cadillac code can vary depending on the specific cause of the issue. In general, replacing a faulty engine oil temperature sensor can cost between $100 and $200 for the part, with additional labor costs ranging from $80 to $150 per hour. If wiring or ECM issues are to blame, the repair costs may increase accordingly. It's advisable to consult with a trusted mechanic or auto repair shop for a more accurate cost estimate based on the specific circumstances of the vehicle. Labor rates at auto repair shops can vary based on location, vehicle make and model, and other factors, so it's important to consider these variables when estimating repair costs.

Need more information about the P1187 Cadillac code?

Need more information on how to fix the P1187 Cadillac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1187 Cadillac code diagnosed by a professional: Find a repair shop in your area

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 P1187 Cadillac Code

No Frequently Asked Questions about P1187 Cadillac Code found.

Discuss the causes and fixes for P1187 Cadillac OBDII Code

Code P1187 Cadillac comments

No comments found for this page.