CONT GP 9X5566 - Caterpillar

Check Engine Lamp.Engine Serial Nos. 43Z1-344: With the engine start switch key in START position but the engine not running, the check engine lamp will stay on for five seconds, momentarily blink off, then stay on for five more seconds. This tests the lamp to check if it is functioning properly. The lamp will then flash three times, pause, flash four times (Code 34). Code 34 indicates No Engine RPM. Code 34 is followed by any active codes. When the engine is not running, Code 34 does not indicate a problem.
Engine Serial Nos. 43Z345-Up: With the engine start switch key in START position but the engine not running, the check engine lamp will stay on for five seconds, momentarily blink off, then stay on for five more seconds. This tests the lamp to check if it is functioning properly. If there are any active codes, other than Code 34, they will be displayed at this time.
All engines: When the engine is first started, the check engine lamp will stay on for five seconds, momentarily blink off, then stay on for five more seconds. If the lamp does not go off after five seconds, an active engine code has been detected.
When an ACTIVE code is detected, the engine check lamp will turn ON and remain ON, momentarily blinking off every five seconds. If the condition generating the code occurs only for a brief moment, the lamp will go OFF after five seconds, and the code is logged by the Engine Control Module (ECM).
The diagnostic toggle switch can be used to interrogate the Engine Control Module (ECM) for engine status. This toggle switch is located under the cover of the left side fuse panel in the operator's compartment. With the engine start switch key in the ON position or the engine running, push and hold the toggle switch. Once the code(s) begin to flash, the diagnostic switch can be released.
Once activated, the check engine lamp will begin to flash indicating a two digit code. The sequence of flashes represents the system's diagnostic message. The first sequence of flashes adds up to the first digit of the code. After a two second pause, a second sequence of flashes will occur which represents the second digit of the code. Any additional codes will follow, after a pause, and are displayed in the same manner.
An ACTIVE diagnostic code represents a problem that should be investigated. See the following chart for a list of the diagnostic code numbers. If there is an ACTIVE code and the tractor is not noticeably malfunctioning, operation may be continued with caution. However, the problem(s) should be investigated and corrected AS SOON AS POSSIBLE.
Repairing the cause of an ACTIVE code will cause the code to be cleared. Intermittent faults should also be watched for as they may lead to a "hard" failure that will disable the machine.