F8048 Force BOWED WASHER

Table 1
Diagnostic Codes Table    
Code    Conditions which Generate this Code    System Response    
401-5 Ignition Transformer Secondary #1 : Current Below Normal
402-5 Ignition Transformer Secondary #2 : Current Below Normal
403-5 Ignition Transformer Secondary #3 : Current Below Normal
404-5 Ignition Transformer Secondary #4 : Current Below Normal
405-5 Ignition Transformer Secondary #5 : Current Below Normal
406-5 Ignition Transformer Secondary #6 : Current Below Normal
407-5 Ignition Transformer Secondary #7 : Current Below Normal
408-5 Ignition Transformer Secondary #8 : Current Below Normal
409-5 Ignition Transformer Secondary #9 : Current Below Normal
410-5 Ignition Transformer Secondary #10 : Current Below Normal
411-5 Ignition Transformer Secondary #11 : Current Below Normal
412-5 Ignition Transformer Secondary #12 : Current Below Normal
413-5 Ignition Transformer Secondary #13 : Current Below Normal
414-5 Ignition Transformer Secondary #14 : Current Below Normal
415-5 Ignition Transformer Secondary #15 : Current Below Normal
416-5 Ignition Transformer Secondary #16 : Current Below Normal     With the engine cranking, the Electronic Control Module (ECM) detects a low current flow in the secondary circuit for the ignition transformer.
There is a problem with the transformer ground.
An open circuit in the secondary winding of the transformer
There is a problem with the connection to the spark plug terminal post.
The spark plug has internal damage or an open circuit.
The spark plug gap is too wide.     The status of the transformer secondary output is set to 120 percent.
The alarm output is activated.
The code is logged.    
Table 2
Diagnostic Codes Table    
Code    Conditions which Generate this Code    System Response    
401-6 Ignition Transformer Secondary #1 : Current Above Normal
402-6 Ignition Transformer Secondary #2 : Current Above Normal
403-6 Ignition Transformer Secondary #3 : Current Above Normal
404-6 Ignition Transformer Secondary #4 : Current Above Normal
405-6 Ignition Transformer Secondary #5 : Current Above Normal
406-6 Ignition Transformer Secondary #6 : Current Above Normal
407-6 Ignition Transformer Secondary #7 : Current Above Normal
408-6 Ignition Transformer Secondary #8 : Current Above Normal
409-6 Ignition Transformer Secondary #9 : Current Above Normal
410-6 Ignition Transformer Secondary #10 : Current Above Normal
411-6 Ignition Transformer Secondary #11 : Current Above Normal
412-6 Ignition Transformer Secondary #12 : Current Above Normal
413-6 Ignition Transformer Secondary #13 : Current Above Normal
414-6 Ignition Transformer Secondary #14 : Current Above Normal
415-6 Ignition Transformer Secondary #15 : Current Above Normal
416-6 Ignition Transformer Secondary #16 : Current Above Normal     With the engine cranking, the ECM detects a high current flow in the secondary circuit for the ignition transformer.
A short circuit in the secondary winding of the transformer
The spark plug is fouled.
The spark plug gap is too close.     The status of the transformer secondary output is set to zero percent.
The alarm output is activated.
The code is logged.    The transformers are located on the covers for the valve lifters. Each transformer is grounded to a cover via the transformer mounting flange. The transformers initiate combustion by providing high voltage to the spark plugs. The positive output from the transformer secondary circuit is delivered to the connection for the spark plug.
Illustration 1 g02850759
(1) Wire seal (2) Lockwire (3) Ignition harness (4) Transformer (5) Terminal for the spark plug extension (6) Extension (7) Terminal for the spark plug (8) Spark plug (9) Mounting flange for the transformerThe secondary circuit of the transformer provides an initial 8,000 to 37,000 V to the spark plug via the extension. This voltage ionizes the spark plug gap. This voltage is then reduced to about 1000 V. The total duration of the spark is approximately 400 µ seconds.The ECM can diagnose the secondary circuit of the ignition transformers for open circuits and/or for short circuits. The ECM monitors the primary circuit of the ignition transformers. Secondary open circuits and short circuits 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.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 not 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. Oxidation of the spark plug internal components will affect the readings of those meters.Logged diagnostic codes provide a historical record. Before you begin this procedure, use the Caterpillar Electronic Technician (ET) to print the logged codes to a file.The most likely cause of the diagnostic code is a problem with the spark plug. The next likely cause is a poor electrical connection or a problem with the extension. The least likely cause is a problem with an ignition transformer.Test Step 1. Check the Status Screen of Cat ET for the Outputs of the Transformer Secondary Circuits
Turn the engine control switch to the OFF/RESET position. Switch the 16 amp circuit breaker for the ECM OFF.
Connect Cat ET to the service tool connector on the terminal box.
Switch the 16 amp circuit breaker for the ECM ON. Turn the engine control switch to the STOP position.
Use Cat ET to view the status screens for the ignition secondary voltage. The status screens must be built by the user. Use the tools that are in Cat ET in order to create the screens for the ignition secondary voltage. Examples of the status screens are shown in Table 3:
Table 3
Status Screens on Cat ET    
Screen 1
Group 8     Screen 2
Group 9    
"Cylinder #1 Transformer Secondary