C1.7 and C2.2 Industrial Engine Caterpillar

Engine Overspeeds

Usage:

C1.7 G34

This procedure covers the following diagnostic trouble code:

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Table 1
Diagnostic Trouble Codes for Engine Overspeed
J1939 Code	Code Description	Comments
190-0	Engine Overspeed Warning - Level 3	The engine has exceeded the value that is programmed into the Electronic Control Module (ECM) for 0.6 seconds. There are no diagnostic trouble codes for the speed/timing sensors. The engine has been running for at least 3 seconds. The shutdown lamp will illuminate and the engine will stop.

The ECM limits the flow of fuel to prevent the engine speed from exceeding the value that is programmed into the ECM.

If the engine speed exceeds the value that is programmed into the ECM, the ECM illuminates the warning lamp and the shutdown lamp. A 190-0 code becomes active for the current keyswitch cycle. When the keyswitch is cycled to the OFF position and back to the ON position, the 190-0 code becomes logged.

The history of engine overspeeds can be viewed on the electronic service tool.

Probable Causes

Diagnostic codes
Proceeding down steep grades (if applicable)
Turbocharger
Combustible gases or liquid in the Intake air

Recommended Actions

Note: The procedures have been listed in order of probability. Complete the procedures in order.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Diagnostic Codes A. Download the Product Status Report before troubleshooting or clearing any diagnostic codes. Note: The downloaded information will be required by the DSN if troubleshooting assistance is needed. B. Use the electronic service tool to check for active or logged codes.	Diagnostic codes	Result: A diagnostic code is not active or logged. Return the unit to service. Result: A 190-0 diagnostic code is present. Proceed to Test Step 2.
2. Proceeding Down Steep Grades (If Applicable) A. Make sure that the operator understands the correct operation of the machine when operating on steep grades.	Steep grades	Result: Steep grades are the cause of the overspeed. Control the engine speed during steep grades. Result: Steep grades are not the cause of the overspeed. Proceed to Test Step 3.
3. Turbocharger Note: The turbocharger that is installed on the engine is a nonserviceable item. If any mechanical fault exists, then the turbocharger must be replaced. A. Check for any oil that may be leaking into the intake air.	Turbocharger	Result: A turbocharger is leaking oil into the intake air. Repair: Replace the turbocharger. Result: A turbocharger is not leaking oil into the intake air. Proceed to Test Step 4.
4. Combustible Gases or Liquid in the Intake Air A. Check for combustible gases in the surrounding atmosphere. B. Check for combustible liquid in the air intake.	Air quality	Result: The atmosphere has combustible gases. Do not operate the engine in an environment with combustible gases. Result: There is combustible liquid in the air intake. Repair: Remove the liquid. Investigate and rectify the cause of liquid ingestion Result: The intake air does not contain combustible gases. Contact the Dealer Solutions Network (DSN).