AutoCodes – GMC – P1189 GMC

P1189 GMC Code - Engine Oil Pressure Switch Fault

Quick Answer

The low oil pressure sensor is normally closed. Common causes include Faulty Engine Oil Pressure Switch, Engine Oil Pressure Switch harness is open or shorted, Engine Oil Pressure Switch circuit poor electrical connection. 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: P1189 GMC indicates Engine Oil Pressure Switch Fault.
Common causes: Common causes include Faulty Engine Oil Pressure Switch, Engine Oil Pressure Switch harness is open or shorted, Engine Oil Pressure Switch circuit poor electrical connection.
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.

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Code Popularity 5,410

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1189 GMC Description

The low oil pressure sensor is normally closed. When oil pressure increases above 1 to 4.5 psi the switch contacts open. The Powertrain Control Module (PCM) supplies 12 volts to the oil pressure input circuit. With low oil pressure the 12 volts is pulled low to ground. This diagnostic tests for a open condition of the oil pressure switch circuit. If the engine has been off long enough for engine temperature to drop by 10Â°C, then a shorted (low oil pressure) condition of the circuit should be observed prior to engine running.

OBDII Code P1189 GMC - Engine Oil Pressure Switch Fault - AutoCodes.com — P1189 GMC Code - Engine Oil Pressure Switch Fault

What does this mean?

What are the Possible Causes of the DTC P1189 GMC?

Faulty Engine Oil Pressure Switch
Engine Oil Pressure Switch harness is open or shorted
Engine Oil Pressure Switch circuit poor electrical connection

How to Fix the DTC P1189 GMC?

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 P1189 GMC 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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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 P1189 GMC Code

1. What are the common symptoms of OBDII code P1189 GMC (Engine Oil Pressure Switch Fault)?

- Common symptoms include illuminated oil pressure warning light on the dashboard, erratic oil pressure readings, and potential engine performance issues.

2. What are the possible causes of OBDII code P1189 GMC?

- The code can be triggered by a faulty engine oil pressure switch, low engine oil level, oil leaks, or wiring issues related to the oil pressure sensor.

3. How can I diagnose the cause of OBDII code P1189 GMC?

- Diagnose by checking the engine oil level, visually inspecting for oil leaks, testing the oil pressure switch, and inspecting the wiring connections for any damage.

4. Can driving with OBDII code P1189 GMC cause further damage to the vehicle?

- Driving with this code can potentially cause engine damage due to insufficient lubrication from inaccurate oil pressure readings.

5. How do I repair OBDII code P1189 GMC (Engine Oil Pressure Switch Fault)?

- Repair involves replacing the faulty oil pressure switch, addressing any oil leaks, topping up the engine oil to the correct level, and ensuring proper wiring connections.

6. Is it safe to reset the OBDII code P1189 GMC without fixing the underlying issue?

- It is not recommended to reset the code without addressing the root cause, as the problem may persist and potentially lead to more severe engine issues.

7. Can a DIY enthusiast fix OBDII code P1189 GMC at home?

- Depending on the skill level, DIY enthusiasts can replace the oil pressure switch themselves, but it's crucial to ensure proper diagnosis and repair to avoid further complications.

8. How often should the engine oil pressure switch be replaced to prevent OBDII code P1189 GMC from recurring?

- It is recommended to replace the engine oil pressure switch as part of regular maintenance or whenever symptoms of malfunction arise to prevent the code from recurring.

9. Are there any preventive measures to avoid OBDII code P1189 GMC in the future?

- Regularly checking and maintaining proper engine oil levels, addressing any oil leaks promptly, and inspecting the oil pressure switch during routine service can help prevent this code from occurring.

10. Can a malfunctioning oil pressure switch affect other engine components?

- Yes, a malfunctioning oil pressure switch can affect other engine components by causing improper lubrication, potentially leading to accelerated wear and damage if not addressed promptly.