C7 and C9 On-Highway Engines Caterpillar

Use this procedure to troubleshoot the following codes:

Components for the Ignition System

There are two possible locations for the ignition coil. Refer to Illustrations 1 and 2.

Illustration 1	g01339562
Components for the ignition system near the ignition coil The ignition coil is located near the oil filter. (1) Harness connector for the ignition transformer (2) Ground wire from terminal 2 to the engine block (3) Insulation material for the ignition wire (4) Engine block ground (5) Ignition wire (6) Ground wire between the engine block and the ARD combustion head (7) Ignition coil

Illustration 2	g01341479
Components for the ignition system near the ignition coil The ignition coil is located above exhaust manifold (8) . (3) Insulation material for the ignition wire (4) Engine block ground (5) Ignition wire (6) Ground wire between the engine block and the ARD combustion head (7) Ignition coil (8) Exhaust manifold

Illustration 3	g01339565
Components for the ignition system (5) Ignition wire (6) Ground wire between the engine block and the ARD combustion head (9) Ground point on the ARD combustion head (10) Spark plug

Illustration 4	g01339607
Typical ARD combustion head (10) Spark plug (11) Spark plug's electrode (12) Ground probe

Illustration 5	g01395281
Information for the ignition circuit

System Operation

The ARD ignition system has two circuits. The primary circuit is between the ECM and the ignition coil. The secondary circuit is between the ignition coil and the ARD combustion head. The current flow through the primary circuit indicates the condition of the primary circuit and of the secondary circuit. The ECM monitors the current flow through the primary circuit. In this way, the ECM is able to detect problems with the primary circuit and the secondary circuit. A problem with either circuit must persist for approximately 20 seconds in order for the ECM to activate a -5 code or -6 code.

The ECM creates an ignition pulse 12 times each second whenever the engine speed is greater than 500 rpm. Wiring sends the signal to the primary side of the ignition coil. The ignition coil may be located near the oil filter or above the exhaust manifold.

The ignition coil converts the ignition pulse into a high voltage signal. Ignition wire (5) connects the ignition coil's output to spark plug (10). The spark plug is threaded into the ARD combustion head. The spark jumps between the spark plug's electrode (11) and ground probe (12) inside the ARD combustion head. The spark ignites the air/fuel mixture.

Ground wire (6) ensures that the secondary ignition circuit is complete between the ARD combustion head and the ignition coil. The ground wire runs inside the insulation (3) that is wrapped around ignition wire (5). The ground wire is connected to two ground points. One ground point (9) is on the ARD combustion head. One ground point (4) is on the engine block near the ignition transformer.

Disabling the ARD Ignition System

There are two ways to disable the ARD ignition system.

"Disable" switch (if equipped) In the Cab - A 3703-31 code is active when the "Disable" switch is disabling the ARD.

"ARD Manual Disable Status" Parameter on Cat ET - A 3714-31 code is active when the "ARD Manual Disable Status" parameter is disabling the ARD.

Features on Cat ET for the ARD Ignition System

ARD Ignition Test - The test operates the ARD for approximately five minutes while the engine is running. The test determines if the ARD can generate heat. If the ARD cannot generate heat, a diagnostic code is activated. The code indicates the specific problem with the ARD.

ARD Ignition Transformer Primary Status Override - This override turns on the ARD ignition system while the engine is not running. Avoid contacting the ignition system components and the ignition system wiring while this override is on.

Illustrations 6 and 7 describe accessing the override.

Illustration 6	g01396661
Access the "System Troubleshooting Settings" menu.

Illustration 7	g01404376
Change the "ARD Ignition Transformer Primary Status" to "On".

Test Step 1. Identify the Problem

1. Establish communication between Cat ET and the engine ECM. Verify that the service tool is communicating on both data links.

2. If there is a logged 3473-31 code, look for the following logged codes:
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   Table 2

   Logged Codes That Relate to a 3473-31 Diagnostic Trouble Code
   Logged Codes in Addition to a 3473-31 Code		Condition Which Causes the Code	Corrective Action
   3556-7		The nozzle inside the ARD combustion head is fouled.	Refer to Troubleshooting, "ARD Nozzle - Test".
   4077-17		The pilot fuel pressure is low.	Refer to Troubleshooting, "Fuel System Pressure - Test".
   3832-17		The flow of combustion air to the ARD is low.	Refer to Troubleshooting, "ARD Combustion Air - Test".
   520192-15 or 520192-16		The flow of clean gas is higher than the desired value.	Refer to Troubleshooting, "Clean Gas Induction - Test".
   None of the above codes are logged.			A problem with the ignition circuit is the most likely cause of a logged 3473-31 code with no additional codes. Refer to the "Results" section of this test step.

Expected Result:

A 3473-31 code is logged. There is an additional logged code that relates to the "failure to ignite" condition.

Results:

• A 3473-31 code is logged. There is an additional logged code that relates to the "failure to ignite" condition. -

  Repair: Perform the appropriate corrective action according to Table 2.

  STOP

• A 4265-6 code is logged. - Proceed to Test Step 11.

• A 3473-31 code is logged. There is not an additional logged code that relates to the "failure to ignite" condition. - Proceed to Test Step 2.

• A 3484-5 or 3484-6 code is logged. There may be a problem with the ignition circuit. - Proceed to Test Step 2.

Test Step 2. Inspect the Components

Note: Carefully following this procedure is a good way to identify wiring problems.

1. Visually inspect the components for the ARD ignition system. Look for the following problems:
   • Loose connections or damaged connectors

   • Moisture on the connectors or the wiring

   • Damage that is caused by excessive heat

   • Damage that is caused by chafing

   • Improper routing of wiring

   • Damaged insulation

2. Verify that each end of ground wire (6) is securely connected to both ground points.

3. Push on the boot on each end of the ignition wire. This tests whether the clip inside the boot is connected to the spark plug and to the ignition coil. There should not be a "click" when you push the boot onto either part. If you felt a "click", the clip inside the boot was not connected.

4. Pull on the end of each harness wire at the 3-pin connector for the ignition coil. This test verifies that the wire is crimped to the terminal and that the terminal is inserted into the connector.

Expected Result:

A wire end is not connected or a wire is damaged.

Results:

• There is a problem with the wiring. A wire end is not connected or a wire is damaged. -

  Repair: Repair the wiring. Replace parts, if necessary.

  Proceed to Test Step 3. If a 3473-31 diagnostic trouble code is logged, proceed to Test Step 5.

• The wiring is OK. - If a 3484-5 or 3484-6 diagnostic trouble code is logged, proceed to Test Step 3. If a 3473-31 diagnostic trouble code is logged, proceed to Test Step 5.

Test Step 3. Check the Ignition System

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

1. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system. The ARD ignition system must operate for 20 seconds in order for a diagnostic trouble code to become active.

2. Look for a 3484-5 or 3484-6 diagnostic trouble code.

Expected Result:

A 3484-5 or 3484-6 diagnostic trouble code becomes active after the override has been running for 20 seconds.

Results:

• A 3484-5 diagnostic trouble code becomes active after the override has been running for 20 seconds. - Proceed to Test Step 8.

• A 3484-6 diagnostic trouble code becomes active after the override has been running for 20 seconds. - Proceed to Test Step 9.

• A 3484-5 or 3484-6 does not become active after the override has been running for 20 seconds. - Proceed to Test Step 4.

Test Step 4. Check the ARD

1. Turn off the ARD ignition system by disabling the override.

2. Start the engine. Use Cat ET to run the "ARD Ignition Test". The test runs for approximately five minutes.

Expected Result:

The "ARD Ignition Test" is unsuccessful. A 3473-31 diagnostic trouble code becomes active.

Results:

• The "ARD Ignition Test" is unsuccessful. A 3473-31 diagnostic trouble code becomes active. - Proceed to Test Step 5.

• The "ARD Ignition Test" passes. - Proceed to Test Step 7.

Test Step 5. Check for Spark Voltage at the Spark Plug

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Illustration 8	g01339970
305-2391 Spark Indicator (13) End of the spark indicator (14) "17" location on the tool (15) Clip on the adjustable end of the spark indicator (16) "20" indication on the tool

1. Turn clip (15) until the tip of the threaded rod is set to location (14) .

2. Disconnect the ignition wire from the spark plug.

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Illustration 9	g01341351
Typical configuration (5) Ignition wire (9) Ground point

3. Connect the spark indicator between ignition wire (5) and ground point (9) .

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

4. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system. The ARD ignition system must operate for 20 seconds in order for a diagnostic trouble code to become active.

Expected Result:

There are sparks inside the spark indicator.

Results:

• There are sparks inside the spark indicator. - Turn off the ARD ignition system by disabling the override. Proceed to Test Step 7.

• There are no sparks inside the spark indicator. - Turn off the ARD ignition system by disabling the override. Proceed to Test Step 6.

Test Step 6. Check for Spark Voltage at the Ignition Coil Output

1. Connect the ignition wire to the spark plug. Verify that the connection is tight.

2. Fabricate a jumper wire with an alligator clip on each end. Make the wire approximately 12 inches long.

3. Disconnect the ignition wire from the ignition coil.

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Illustration 10	g01341421
Acceptable corrosion on the ignition coil output (17) Acceptable corrosion (18) Acceptable corrosion

4. Inspect the terminal at the ignition coil output. Illustration 15 shows acceptable corrosion.

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Illustration 11	g01341375
Typical configuration (4) Engine block ground (15) Clip on the adjustable end of the spark indicator (19) Ignition coil output (20) Jumper wire

5. Attach clip (15) to ignition coil output (19). Connect jumper wire (20) to end (13) and to engine block ground (4) .

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

6. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system. The ARD ignition system must operate for 20 seconds in order for a diagnostic trouble code to become active.

7. Look for sparks inside the spark indicator.

8. Turn off the ARD ignition system by disabling the override.

Expected Result:

There were sparks inside the spark indicator.

Results:

• There were sparks inside the spark indicator. The ignition coil is OK. However, there was no spark at the spark plug. There is a problem with the ignition wire. -

  Repair: Replace the ignition wire. Verify that each end of the new ignition wire is fully seated.

  Proceed to Test Step 10.

• There are no sparks inside the spark indicator. -

  Repair: Replace the ignition coil. Connect the ignition wire. Verify that the end of the ignition wire is connected tightly.

  Proceed to Test Step 10.

Test Step 7. Clean the Components in the ARD Combustion Head

1. Remove the spark plug from the ARD combustion head.

2. Clean the ground probe inside the ARD combustion head by running a 305-2389 Plug Bore Brush through the hole in the ARD combustion head. Run the brush through the hole several times.

3. Inspect the spark plug. Look for the following problems:

   Carbon Deposits - Use a nonmetallic cleaning pad to carefully clean the spark plug.

   Bent Probe - If the probe appears to be bent, replace the spark plug. Otherwise, install the original spark plug. Refer to the Specifications manual for the correct torque value.

   Note: The spark plug may be damaged if the spark plug is dropped. Do not install a spark plug that has been dropped.

Expected Result:

The components are clean.

Results:

• The components are clean. - Proceed to Test Step 10.

Test Step 8. Check the Wiring for an Open Circuit

1. Disconnect the harness connector for the ignition coil.

2. Inspect the terminals of each connector. Verify that the wedges are installed and that the seals are in good condition.

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Illustration 12	g01340874
3-pin connector for the ignition coil

3. Connect a jumper wire between terminals 1 and 3 of the harness connector for the ignition coil.

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

4. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system. The ARD ignition system must operate for 20 seconds in order for a diagnostic trouble code to become active.

5. Look for an active 3484-5 diagnostic code.

6. Turn off the ARD ignition system by disabling the override.

Expected Result:

A 3484-5 code became active.

Results:

• A 3484-5 code became active. The ECM did not detect the jumper wire. There is an open circuit in the wiring between the ignition coil and the P2 connector on the ECM. There may be a problem inside a connector. -

  Repair: Locate the problem in the wiring. Make the necessary repairs.

  Proceed to Test Step 10.

• A 3484-6 code became active. The ECM detected the jumper wire. -

  Repair: Replace the ignition coil.

  Proceed to Test Step 10.

Test Step 9. Check the Wiring for a Short Circuit

1. Disconnect the harness connector for the ignition coil.

2. Inspect the terminals of each connector. Verify that the wedges are installed and that the seals are in good condition.

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

3. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system. The ARD ignition system must operate for 20 seconds in order for a diagnostic trouble code to become active.

4. Look for an active 3484-6 diagnostic code.

5. Turn off the ARD ignition system by disabling the override.

Expected Result:

A 3484-6 code became active.

Results:

• A 3484-6 code became active. There is a short circuit in the wiring between the ignition coil and the P2 connector on the ECM. -

  Repair: Locate the problem in the wiring. Make the necessary repairs.

  Proceed to Test Step 10.

• A 3484-5 code became active. The ECM detected the open circuit. -

  Repair: Replace the ignition coil.

  Proceed to Test Step 10.

Test Step 10. Check the ARD for Proper Operation

1. Activate the ARD Ignition Test. The test runs for approximately five minutes.

Expected Result:

The test is successful.

Results:

• The test is successful. - Return the vehicle to service. The DPF lamp may be on. However, the ECM will command a transient regeneration. This will turn off the DPF lamp.STOP

• The test is not successful. -

  Repair: Contact your local Caterpillar Technical Communicator for further assistance. Attach the data log to the warranty report in SIMSi.

  STOP

Test Step 11. Inspect the Ignition Wire

Note: Carefully following this procedure is a good way to identify wiring problems.

1. Visually inspect the ignition wire between the ignition coil and the ARD combustion head. Look for the following problems:
   • Loose connections or damaged connectors

   • Moisture on the connectors or the ignition wire

   • Damage to the ignition wire that is caused by excessive heat

   • Damage to the ignition wire that is caused by chafing

   • Improper routing of the ignition wire

   • Damaged insulation on the ignition wire

2. Push on the boot on each end of the ignition wire. This tests whether the clip inside the boot is connected to the spark plug and to the ignition coil. There should not be a "click" when you push the boot onto either part. If you felt a "click", the clip inside the boot was not connected.

Expected Result:

The ignition wire is not damaged.

Results:

• The ignition wire is OK. - Proceed to Test Step 12.

• The ignition wire is damaged. -

  Repair: Replace the ignition wire.

  Proceed to Test Step 12.

Test Step 12. Disconnect the ARD Combustion Head From the Secondary Circuit and Test the Secondary Circuit

The 4265-6 code is caused by a problem in the secondary circuit. The problem may be outside of the ARD combustion head or inside the ARD combustion head. This test step disconnects the ARD combustion head from the circuit. If the code does not occur when the ARD combustion head is not in the circuit, the problem is inside the ARD combustion head.

The ECM checks for a 4265-6 code when the engine is running and the ARD starts to operate. The ECM can also check for a 4265-6 code when the engine is not running. The following conditions must be present in order for the ECM to check for a 4265-6 code when the engine is not running:

• The ARD Ignition Transformer Primary Status override on Cat ET is used to activate the ignition system.

• The "Active Wiggle Test" is enabled.

These two conditions cause the ECM to check for a 4265-6 code. The ECM requires approximately six seconds in order to check the circuit.

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Illustration 13	g01339970
305-2391 Spark Indicator (13) End of the spark indicator (14) "17" location on the tool (15) Clip on the adjustable end of the spark indicator (16) "20" indication on the tool

1. Turn clip (15) until the tip of the threaded rod is set to location (14) .

2. Disconnect the ignition wire from the spark plug.

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Illustration 14	g01341351
Typical configuration (5) Ignition wire (9) Ground point

3. Connect the spark indicator between ignition wire (5) and ground point (9) .

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

4. Use the ARD Ignition Transformer Primary Status override on Cat ET to activate the ARD ignition system.

5. Use Cat ET to activate the "Wiggle Test".

6. Wait for approximately six seconds.

7. Stop the "Wiggle Test".

8. Use the ARD Ignition Transformer Primary Status override on Cat ET to deactivate the ARD ignition system.

Expected Result:

A 4265-6 code does not become active during the test.

Results:

• A 4265-6 code does not become active during the test. - The ignition system works correctly when the ARD combustion head is not in the secondary circuit. There is a problem inside the ARD combustion head. Proceed to Test Step 13 in order to check the ARD combustion head.

• A 4265-6 code becomes active during the test. - There is a problem with the circuit on the outside of the ARD combustion head. Proceed to Test Step 14 in order to test the ignition coil.

Test Step 13. Check the Components in the ARD Combustion Head

1. Remove the spark plug from the ARD combustion head.

2. Clean the ground probe inside the ARD combustion head by running a 305-2389 Plug Bore Brush through the hole in the ARD combustion head. Run the brush through the hole several times.

3. Install a new spark plug.

4. Connect the ignition wire to the spark plug. Verify that the ignition wire is firmly connected to the spark plug.

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

5. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system.

6. Use Cat ET to activate the "Wiggle Test".

7. Wait for approximately six seconds.

8. Stop the "Wiggle Test".

9. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn off the ARD ignition system.

Expected Result:

A 4265-6 code does not occur during the test.

Results:

• A 4265-6 code does not occur during the test. - The problem inside the ARD combustion head has been resolved. The problem may have been caused by a fouled nozzle inside the ARD combustion head. Proceed to Test Step 15 in order to check the condition of the nozzles.

• A 4265-6 code occurred during the test. - The ARD combustion head is OK. There is a problem with the circuit on the outside of the ARD combustion head. Proceed to Test Step 14 in order to test the ignition coil.

Test Step 14. Determine If the Ignition Coil Is Causing the Problem

1. Remove the spark indicator from the ARD combustion head if the spark indicator is connected to the ARD combustion head. Connect the ignition wire to the spark plug. Verify that the ignition wire is firmly connected to the spark plug.

2. Fabricate a jumper wire with an alligator clip on each end. Make the wire approximately 12 inches long.

3. Disconnect the ignition wire from the ignition coil.

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Illustration 15	g01341421
Acceptable corrosion on the ignition coil output (17) Acceptable corrosion (18) Acceptable corrosion

4. Inspect the terminal at the ignition coil output. Illustration 15 shows acceptable corrosion.

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Illustration 16	g01341375
Typical configuration (4) Engine block ground (15) Clip on the adjustable end of the spark indicator (19) Ignition coil output (20) Jumper wire

5. Attach clip (15) to ignition coil output (19). Connect jumper wire (20) to end (13) and to engine block ground (4) .

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The ignition system may cause an electrical shock hazard, which may cause personal injury or death. Avoid contacting the ignition system components and the ignition system wiring during operation.

6. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn on the ARD ignition system.

7. Use Cat ET to activate the "Wiggle Test".

8. Wait for approximately six seconds.

9. Stop the "Wiggle Test".

10. Use the ARD Ignition Transformer Primary Status override on Cat ET to turn off the ARD ignition system.

Expected Result:

A 4265-6 code occurred during the test.

Results:

• A 4265-6 code occurred during the test. - The ignition coil is causing the code to occur.

  Repair: Perform the following procedure:

  1. Replace the ignition coil.

  2. Connect the spark indicator to the output of the new ignition coil.

  3. Verify that the 4265-6 does not recur after the new ignition coil is installed.

  4. Remove the spark indicator.

  5. Connect the ignition wire to the ignition coil. Verify that the ignition wire is firmly connected to the ignition coil.

  Proceed to Test Step 15 in order to check the condition of the nozzles inside the ARD combustion head.

• A 4265-6 code did not occurr during the test. - The ignition coil is OK. The ignition wire has a problem.

  Repair: Perform the following procedure:

  1. Replace the ignition wire. Be sure to route the new ignition wire correctly. Use the appropriate clips to secure the ignition wire to the engine.

  2. Verify that a 4265-6 does not occur after the new ignition wire is installed.

  Proceed to Test Step 15 in order to check the condition of the nozzles inside the ARD combustion head.

Test Step 15. Check the Condition of the Nozzles Inside the ARD Combustion Head by Performing a Stationary Regeneration

1. If the following codes are active, clear the codes. The ARD will not ignite if the codes are active.
   • 3703-31 Diesel Particulate Filter Active Regeneration Inhibited Due to Inhibit Switch

   • 3714-31 Aftertreatment #1 Regeneration Manually Disabled

2. Click the "Disconnect" icon on Cat ET in order to disconnect Cat ET from the engine.

3. Turn the keyswitch to the Off position. Wait for five seconds.

4. Turn the keyswitch to the On position.

5. Click the "Connect" icon on Cat ET in order to connect Cat ET to the engine.

6. Start the engine. Allow the engine to idle for three minutes.

7. Start a stationary regeneration by selecting the following menus on Cat ET:
   • "Service"

   • "Service Procedures"

   • "Manual Diesel Particulate Filter Regeneration"

   Cat ET will display a "Waiting On Requirements" window. The ECM will automatically elevate the engine speed to 1400 rpm. If the "Waiting On Requirements" window remains displayed for more than five minutes, abort the regeneration. Then, select the menu options again in order to start the stationary regeneration.

   The duration of the stationary regeneration depends on the soot load in the DPF. The ECM will automatically return the engine speed to low idle after the stationary regeneration is complete.

   Note: The ECM tests the nozzles for plugging after the stationary regeneration is complete. Approximately ten minutes are required in order for the test to provide a result. A 3556-7 code will become active if a nozzle is plugged.

Expected Result:

The stationary regeneration completed successfully.

Results:

• The stationary regeneration completed successfully. - STOP

• The stationary regeneration did not complete successfully. -

  Repair: Check the list of active diagnostic codes. Troubleshoot the code that applies to the failed regeneration.

  STOP