69354A 2 Mercruiser COUPLING ASSEMBLY (MCM)

Table 1
J1939 Code and Description Comments
1393-15
Engine Cylinder #1 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the Electronic Control Module (ECM) detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1394-15
Engine Cylinder #2 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1395-15
Engine Cylinder #3 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1396-15
Engine Cylinder #4 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1397-15
Engine Cylinder #5 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1398-15
Engine Cylinder #6 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1399-15
Engine Cylinder #7 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1400-15
Engine Cylinder #8 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1401-15
Engine Cylinder #9 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1402-15
Engine Cylinder #10 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1403-15
Engine Cylinder #11 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged.
1404-15
Engine Cylinder #12 Ignition Transformer Secondary Output : High - least severe (1) While the engine is started, the ECM detects a low current flow in the primary circuit for the ignition transformer.
The code is logged. The ignition transformers initiate combustion by providing high voltage to the spark plugs. The output from the secondary circuit of the transformer provides voltage to the terminals of the spark plug. The transformers are located underneath the valve covers. Each transformer is grounded to a valve cover via a ground spring.The secondary circuit of the transformer provides an initial 8,000 to 37,000 V to the spark plug. This voltage ionizes the air that is in the spark plug gap and this action generates a spark in the air gap. This voltage is then reduced to about 1,000 V. The total duration of the spark is approximately 400 microseconds.Each Electronic Control Module (ECM) can diagnose the primary circuit of the ignition transformers for open circuits and/or for short circuits. Secondary open circuits and short circuits will not directly shutdown the engine. However, these conditions may lead to misfire which can cause lugging of the engine. Lugging of the engine can cause a shutdown.Note: Ignition transformers that are used with Electronic Ignition Systems (EIS) are not interchangeable with the transformers that are used with ADEM III and up systems. Be sure not to interchange these components on any engine.Caterpillar spark plugs are high-voltage devices with internal resistors. The spark plugs operate at a voltage that is greater than 5,000 V.Most ignition systems are affected by resistance in the secondary circuit. If a measurement of the resistance is desired, a megohmmeter must be used. A low voltage multimeter will not provide a reliable reading of the resistance because oxidation of the spark plug internal components will affect the readings for those meters.
Table 2
Parameters for the Status Screens on Cat ET
Screen 1 Screen 2
"Cylinder #1 Transformer Secondary Output Voltage Percentage" "Cylinder #2 Transformer Secondary Output Voltage Percentage"
"Cylinder #3 Transformer Secondary Output Voltage Percentage" "Cylinder #4 Transformer Secondary Output Voltage Percentage"
"Cylinder #5 Transformer Secondary Output Voltage Percentage" "Cylinder #6 Transformer Secondary Output Voltage Percentage"
"Cylinder #7 Transformer Secondary Output Voltage Percentage" "Cylinder #8 Transformer Secondary Output Voltage Percentage"
"Cylinder #9 Transformer Secondary Output Voltage Percentage" "Cylinder #10 Transformer Secondary Output Voltage Percentage"
"Cylinder #11 Transformer Secondary Output Voltage Percentage" "Cylinder #12 Transformer Secondary Output Voltage Percentage"
"Cylinder #13 Transformer Secondary Output Voltage Percentage" "Cylinder #14 Transformer Secondary Output Voltage Percentage"
"Cylinder #15 Transformer Secondary Output Voltage Percentage" "Cylinder #16 Transformer Secondary Output Voltage Percentage"
"Cylinder #17 Transformer Secondary Output Voltage Percentage" "Cylinder #18 Transformer Secondary Output Voltage Percentage"
"Cylinder #19 Transformer Secondary Output Voltage Percentage" "Cylinder #20 Transformer Secondary Output Voltage Percentage"
Table 3
Troubleshooting Test Steps Values Results
1. Use Caterpillar Electronic Technician (ET) to Check the Output of the Transformers
The engine must be running in order for these diagnostic codes to become active.
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Set up two status screens for Cat ET. Refer to table 2.
C. Start the engine. Allow the engine to warm to normal operating temperature. Apply the normal load at rated speed.
D. Monitor the two status screens. Record the value of the output for the secondary circuit of each transformer.
Secondary Output Voltage Percentage
Results: The displayed values are OK.
The displayed value of the output for the secondary circuit of each transformer is between 1 and 90 percent.
Repair: The ignition system components are operating properly. Investigate other possible root causes of the problem. Troubleshoot the symptom. Refer to Troubleshooting, "Symptom Troubleshooting".
Results: At least one of the displayed values are NOT OK.
At least one of