Kohler Engine Diagnostics: Codes, Tools, and Troubleshooting Tips

Kohler engines are widely recognized for their durability and efficiency, powering everything from lawn mowers to generators. However, like any engine, they can encounter issues that require skilled diagnostics. In this blog, we’ll explore the key aspects of Kohler engine diagnostics, including the location of engine codes, the tools needed for effective troubleshooting, specific EFI diagnostics, and best practices for maintaining your Kohler engine in peak condition.

Where is The Kohler Engine Code?

The engine code generally provides essential information about the engine model, type, and specifications. This information plays a crucial role in troubleshooting and ordering the correct replacement parts or accessories. You can locate the engine code in a few common places:

• Engine Block: Look on the front or side of the engine, typically near the starter or oil filter.

• ID Tag: Many Kohler engines have an identification tag affixed to the engine. This tag usually contains the engine model and spec number, along with the engine code.

• User Manual: The user manual often includes diagrams that show where to find the engine code for specific models.

Tools Required For Kohler Engine Diagnostics

• Multimeter: A multimeter will check the electrical components of the engine, including battery voltage, continuity of wires, and other readings.

• Jaltest or Kohler Diagnostic Tool: A specialized scanner can read the trouble codes stored in the engine's electronic control unit (ECU). This is especially necessary for Kohler engines with EFI systems. Request a demo of WholeFleet’s Jaltest software today. 

• Pressure Gauge: This tool is used to measure fuel pressure, ensuring the fuel system is operating correctly.

• Compression Tester: A compression tester checks the engine's internal pressure, helping to diagnose potential issues with valves or piston rings.

• Basic Hand Tools: Wrenches, screwdrivers, and pliers are essential for general maintenance, repairs, and the replacement of parts.

Kohler EFI Diagnostic

Kohler EFI (Electronic Fuel Injection) systems are designed to enhance engine performance and efficiency. However, when a problem arises within the EFI system, having a proper diagnostic approach is essential. Here are steps to perform EFI diagnostics on a Kohler engine:

• Connect the Scanner: Start by connecting your Jaltest diagnostic tool or Kohler diagnostic tool to the engine’s diagnostic port. This will allow you to read any fault codes that may be present.

• Check for Codes: Navigate through the scanner to retrieve any stored trouble codes. These codes will indicate where issues may exist within the engine.

• Analyze Data: Pay attention to live data readings, such as fuel injector pulse width, throttle position, and engine temperature. Anomalies in these readings can help pinpoint problems.

• Perform Tests: Depending on the codes retrieved, you may need to perform specific tests, such as checking the fuel pressure or inspecting the wiring and connectors related to the EFI system.

• Clear Codes and Retest: After addressing any identified issues, clear the fault codes and perform a test run to see if the problem is resolved.

Regular EFI diagnostics not only help in promptly identifying issues but also ensure your engine operates efficiently over its lifespan.

Kohler Engine Fault Code List

Fault Code 13 (Low Oil Pressure)

Meaning: The engine oil pressure is below the acceptable range.

Troubleshooting: Check the oil level; if low, add oil. Inspect for leaks and ensure the oil pump is functioning properly.

Fault Code 21 (High Engine Temperature)

Meaning: The engine is overheating.

Troubleshooting: Check the coolant level and add if necessary. Inspect the radiator for blockages and ensure the cooling fan is operational.

Fault Code 22 (Over Speed)

Meaning: The engine has exceeded its maximum RPM limit.

Troubleshooting: Check for a malfunctioning governor. Ensure the throttle linkage is functioning correctly.

Fault Code 23 (Low Battery Voltage)

Meaning: The battery voltage is too low.

Troubleshooting: Check the battery charge; replace if necessary. Ensure all electrical connections are secure and free from corrosion.

Fault Code 24 (High Battery Voltage)

Meaning: The battery voltage is too high.

Troubleshooting: Inspect the charging system and voltage regulator. Ensure the alternator is working correctly.

Fault Code 25 (Fuel Pressure Low)

Meaning: Indicates insufficient fuel pressure for proper engine operation.

Troubleshooting: Check the fuel tank for level, inspect fuel lines for blockages or leaks, and ensure the fuel pump is functioning.

Fault Code 27 (Faulty Throttle Position Sensor)

Meaning: There is an issue with the throttle position sensor.

Troubleshooting: Inspect the throttle position sensor and its connections. Test the sensor for proper operation and replace it if faulty.

Fault Code 28 (Faulty Engine Coolant Temperature Sensor)

Meaning: The engine coolant temperature sensor is not functioning properly.

Troubleshooting: Check the sensor wiring and connections. Test the sensor’s resistance and replace it if necessary.

Fault Code 29 (Faulty Speed Sensor)

Meaning: There is a malfunction in the speed sensor.

Troubleshooting: Inspect the speed sensor and its wiring. Test the sensor for proper operation and replace it if needed.

Fault Code 30 (Injector Circuit Open/Shorted)

Meaning: The fuel injector circuit has an open or shorted condition.

Troubleshooting: Inspect injector wiring for damage or disconnection. Test the injector and wiring continuity. Replace the injector if necessary.

Best Practices For Keeping Your Kohler Engine In Top Condition

It’s recommended that you take proactive and preventative action to maintain your Kohler engine’s health. Whether you do will have an impact on your engine’s life span. Here are the best practices for keeping the health of your Kohler engine in check.  

• Regular Oil Changes: Change the oil and oil filter according to the manufacturer’s recommendations. Fresh oil ensures that the engine runs smoothly and reduces wear, prolonging your engine’s overall life span. 

• Check Air Filters: Clean or replace air filters regularly to prevent dirt and debris from entering the engine, which can affect performance.

• Inspect Spark Plugs: Regularly check and replace spark plugs as needed to maintain efficient ignition and fuel burn.

• Maintain Fuel System: Use high-quality fuel and consider adding fuel stabilizers if the engine will sit unused for an extended period. Regularly check for any signs of leaks or corrosion in fuel lines.

• Routine Inspections: Conduct regular physical inspections of the engine, checking for loose bolts, worn belts, and electrical connections. This helps catch potential issues early.

• Keep the Engine Clean: Regularly clean the engine exterior to prevent dirt buildup, which can lead to overheating and other issues.

Why Choose Jaltest Diagnostic Software? 

Jaltest is the ultimate solution to diagnosing and maintaining your vehicle. What makes Jaltest different from other diagnostic tools is that its coverage spans across multiple types of vehicles, models, and systems. While other diagnostic software like Kohler’s EFI Diagnostic tool supports only the vehicles made by their own brand, Jaltest supports multiple brands of vehicles, with continuous updates to account for growing companies and innovations across industries. Supported by a user-friendly and intuitive software interface, Jaltest can service multiple vehicles, no matter the make, model, or brand. 

Interested in learning more? Take a look at our pricing guide or contact us to find out if Jaltest is right for you.