BEARING-CAMSHAFT 9N5246 - Caterpillar

System Operation Description:The ignition transformers initiate combustion by providing high voltage to the spark plugs. The positive output from the secondary circuit of the transformer is at the connection for the terminal of the transformer and the terminal of the spark plug. The transformers are located underneath the valve covers. Each transformer is grounded to a valve cover via a ground spring.
Illustration 1 g01046429
Ignition transformer and spark plug (1) Ground spring (2) 2-pin connector (3) Secondary spark plug terminal (4) Extension (5) O-ring seal (6) Spark plugThe secondary circuit of the transformer provides an initial 8,000 to 32,000 volts to the spark plug. This voltage ionizes the spark plug gap. This voltage is then reduced to about 1000 volts. The total duration of the spark is approximately 400 microseconds.The control module checks the secondary circuit for these faults:
The voltage in the secondary circuit is abnormally low.
The voltage in the secondary circuit is abnormally high.
The voltage in the secondary circuit has reached the maximum limit.
Excessive ignition system noiseAbnormal voltages in a secondary circuit will not directly shut down the engine. However, these conditions may lead to misfire which can cause lugging of the engine. Lugging of the engine can cause a shutdown.If there is excessive ignition system noise and the date of the EIS control module's software is earlier than October 1994, the control module will not shut down the engine. If there is excessive ignition system noise and the date of the EIS control module's software is October 1994 or later than October 1994, the control module will shut down the engine.Test Step 1. Check for Diagnostic Codes for the Secondary Circuits
Connect an electronic service tool to a service tool connector.
Attempt to start the engine. Use the service tool in order to determine if the following codes are activated:
401-00 Ignition Transformer Secondary #1 maintenance needed through 416-00 Ignition Transformer Secondary #16 maintenance needed
401-05 Ignition Transformer Secondary #1 open circuit through 416-05 Ignition Transformer Secondary #16 open circuit
401-06 Ignition Transformer Secondary #1 short to ground through 416-06 Ignition Transformer Secondary #16 short to ground
401-12 Ignition Transformer Secondary #1 noisy component through 416-12 Ignition Transformer Secondary #16 noisy componentNote: If a diagnostic code for the secondary circuit is not currently activated, attempt to repeat the condition that activated the code. Run the engine to full operating temperature.Expected Result:None of the above diagnostic codes are activated.Results:
No Code - The secondary ignition is working properly.STOP
Code - The secondary ignition is not working properly. Proceed to Test Step 2.Test Step 2. Inspect the Transformer
Ignition systems can cause electrical shocks. Avoid contacting the ignition system components and wiring.Do not attempt to remove the valve covers when the engine is operating. The transformers are grounded to the valve covers. Personal injury or death may result and the ignition system will be damaged if the valve covers are removed during engine operation. The engine will not operate without the valve covers.
Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.
Illustration 2 g00893893
(1) Valve