Usage:

• Cat C7 Iap Valve Locations
• Cat C7 Ipr Valve Location
• Cat C7 Iap Valve Location Code
• Cat C7 Iap Valve Location Sensor

The Engine Control Module (ECM) monitors the fuel pressure for the Aftertreatment Regeneration Device (ARD). The ECM sets a diagnostic code if there is a problem with the fuel pressure for the ARD. Table 1 lists the diagnostic codes for the fuel pressure for the ARD.

C7 - C32 Marine Engine Electronics Application and Installation Guide Caterpillar: Confidential Yellow 5 1 Introduction and Purpose This document is intended to provide the necessary information for correct installation of the following Caterpillar engines into marine engine applications: C7/C9, C12, C18, and C32. A current flow of approximately 1.2 A is required in order to open the pilot fuel control valve. However, the higher spring pressure in the main fuel control valve caused the main fuel control valve to remain closed at 1.2 A. A current flow of approximately 1.3 A is required in order for the main fuel control valve. If the connector J204/P204 for. For calculating the fuel injection pressure. Location of the injection actuation pressure control valve.

Fuel System Schematic

Regulation of System Pressure

Fuel transfer pump (9) creates a fuel pressure of approximately 480 kPa (70 psi) when the ARD is off. This pressure is regulated by 500 kPa (72 psi) pressure regulator (17) . The ECM energizes fuel enable valve (18) during an active regeneration. The energized valve moves to position (18B) . This places 1250 kPa (180 psi) pressure regulator (16) into the circuit. The pressure at the outlet of the fuel transfer pump rises to approximately 1725 kPa (250 psi). Fuel at this pressure is available for the ARD.

Component Identification

Lines and Ports

Control of Pilot Fuel Pressure and Main Fuel Pressure

Refer to Illustration 5. There is one electrical circuit for both of the fuel control valves. The valves are connected in series. The ECM creates one PWM command in order to control both of the valves. The maximum current flow through the circuit is approximately 2.5 A.

Each control valve contains a spring. The spring in the pilot fuel control valve is weaker than the spring in the main fuel control valve. Refer to Illustration 6. The lower spring pressure in the pilot fuel control valve causes the pilot fuel control valve to open when the flow of current is low. A current flow of approximately 1.2 A is required in order to open the pilot fuel control valve. However, the higher spring pressure in the main fuel control valve caused the main fuel control valve to remain closed at 1.2 A. A current flow of approximately 1.3 A is required in order for the main fuel control valve to start to open. A current flow of approximately 2.5 A is required in order to open the main fuel control valve.

An electrical problem with the circuit affects both of the control valves. Therefore, both of the control valves are disabled if there is a short circuit or an open circuit.

Test Step 1. Determine the Diagnostic Code

Establish communication between Cat ET and the engine ECM. Look for the following codes:

• 3480-16
• 3480-18
• 4077-16
• 4077-17
• 4077-18

Expected Result:

One of the above codes is present.

Results:

• A 3480-16 code and a 4077-16 code are both present. - The fuel enable valve is stuck open. This causes both fuel pressures to be high.

  Repair: Replace fuel enable valve (18) .

  Proceed to Test Step 4.

• Only a 3480-16 code or a 3480-18 code is present. - The main fuel control valve is not working correctly.

  Repair: Replace main fuel control valve (20) .

  Proceed to Test Step 4.

• Only a 4077-16 code is present. - The pilot fuel control valve is not working correctly.

  Repair: Replace pilot fuel control valve (19) .

  Proceed to Test Step 4.

• A 4077-17 code or a 4077-18 code is present. The fuel system pressure is low. - Proceed to Test Step 2.

Test Step 2. Check the Pressure at the Outlet of the Fuel Transfer Pump

This test step checks the pressure at the outlet of the fuel transfer pump when the ARD is off.

1. Insert a tee in line (39) between the outlet of the fuel transfer pump and the forward fuel manifold. Connect a pressure gauge to the tee.

2. Disable the ARD by setting the value of the 'Data Link Disable ARD Status' parameter to 'Disabled'. The parameter is in 'Emissions Parameters'.

3. Start the engine. Observe the fuel pressure on the gauge. Stop the engine.

Cat C7 Iap Valve Locations

Expected Result:

The outlet pressure for the fuel transfer pump is above 450 kPa (65 psi).

Results:

• The outlet pressure of the fuel transfer pump is above 450 kPa (65 psi). - The outlet pressure of the fuel transfer pump is OK. Proceed to Test Step 3.
• The outlet pressure of the fuel transfer pump is below 450 kPa (65 psi). - The fuel transfer pump has low outlet pressure.

  Repair: The following procedure determines the cause of low pressure at the outlet of the fuel transfer pump. Accomplish the procedure by using the following technique:

  • Repair the component or replace the component if the component is faulty.
  • Start the engine. Check the pressure again.
  • Continue to the next component if the pressure is still below 450 kPa (65 psi).
  1. Replace the primary fuel filter.
  2. Replace 500 kPa (72 psi) pressure regulator (17) .
  Show/hide table
  
  

  Illustration 7	g01388721
  Top view of the front left corner of the engine (5) Rail (7) 600 kPa (86 psi) regulator for the high-pressure fuel pump (8) High-pressure fuel pump

  3. Replace 600 kPa (86 psi) regulator (7) .
  4. Replace fuel transfer pump (9) .

  Proceed to Test Step 3 after the pressure at the outlet of the fuel transfer pump is at least 450 kPa (65 psi).

Test Step 3. Check the Pressure at the Outlet of the Fuel Transfer Pump During an Active Regeneration

The pressure at the outlet of the fuel transfer pump must be at least 450 kPa (65 psi) in order to perform this test step.

1. Enable the ARD by setting the value of the 'Data Link Disable ARD Status' parameter to 'Not Disabled'. The parameter is in 'Emissions Parameters'.

2. Start the engine.

3. Start an active regeneration by setting the value of the 'ARD Override' to 'Active'.

4. Wait for 60 seconds. Observe the fuel pressure on the gauge.

5. Disable the active regeneration by setting the value of the 'ARD Override' to 'Not Active'.

Expected Result:

The outlet pressure of the fuel transfer pump was above 1375 kPa (200 psi).

Results:

• The outlet pressure of the fuel transfer pump was above 1375 kPa (200 psi). - The pressure is OK. The low pilot fuel pressure was caused by the pilot fuel control valve.

  Repair: Replace pilot fuel control valve (20) .

  Proceed to Test Step 4.

• The outlet pressure of the fuel transfer pump was less than 1375 kPa (200 psi). The pressure is low when the ARD is on. -

  Repair: Perform the following procedure. Accomplish the procedure by using the following technique:

  • Repair the component or replace the component if the component is faulty.
  • Activate the ARD after the component is replaced. Check the fuel pressure during the active regeneration. Disable the regeneration after you check the pressure.
  • Continue to the next component if the fuel pressure is still below 1375 kPa (200 psi).
  1. Replace 1250 kPa (180 psi) pressure regulator (16) .
  2. Replace fuel enable valve (18) .
  Continue with this procedure when the fuel pressure is above 1375 kPa (200 psi) during an active regeneration.
  1. Start an active regeneration by setting the value of the 'ARD Override' to 'Active'.
  2. Monitor the value of the 'ARD Pilot Fuel Pressure' during the regeneration. The parameter is in the 'Aftertreatment Regeneration 3' status group. The 'ARD Pilot Fuel Pressure' should be equal to the pressure on the gauge after 5 minutes of operation of the ARD.

     Replace pilot fuel control valve (20) if the pressures are not equal after 5 minutes of operation of the ARD.

  Disable the regeneration and proceed to test step 4 if the pressures are equal after 5 minutes of operation of the ARD.

Test Step 4. Perform a Stationary Regeneration

NOTICE
A 3715-31 code indicates that the DPF contains too much soot. Replace the DPF before clearing this code. If a 3715-31 code is cleared and the Diesel Particulate Filter (DPF) is not replaced, an active regeneration will destroy the DPF.

1. Click the 'Disconnect' icon on Cat ET in order to disconnect Cat ET from the engine.

2. Turn the keyswitch to the OFF position. Wait for 5 seconds.

3. Turn the keyswitch to the ON position.

4. Click the 'Connect' icon on Cat ET in order to connect Cat ET to the engine.

5. Start the engine. Allow the engine to idle for 3 minutes.

6. 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 5 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 10 minutes are required in order for the test to provide a result. A code will become active if the nozzles are plugged.

Results:

• The stationary regeneration completed successfully. - STOP
• The stationary regeneration did not complete successfully. -

  Repair: Refer to Troubleshooting, 'ARD Stationary Regeneration Does Not Activate'.

  STOP

Note: Valve lash is measured between the rocker arm and the bridge for the inlet valves. Valve lash is measured between the rocker arm and the valve stem for the exhaust valve. All of the clearance measurements and the adjustments must be made with the engine stopped. The valves must be fully closed.

Valve Lash Check

An adjustment is not necessary if the measurement of the valve lash is in the acceptable range. Adjust the valve lash while the engine is stopped. The range is specified in Table 1.

Cat C7 Ipr Valve Location

If the measurement is not within this range adjustment is necessary. See Testing And Adjusting, “Valve Lash And Valve Bridge Adjustment”.

Illustration 1 g01320108
Cylinder and Valve Location

(A) Exhaust valve

(B) Inlet valves

Valve Lash and Valve Bridge Adjustment

Cat C7 Iap Valve Location Code

Illustration 2 g01109236
(1) Exhaust rocker arm

(2) Inlet valve bridge

(3) Rocker arm adjustment screw locknut for the exhaust rocker arm

Cat C7 Iap Valve Location Sensor

(4) Rocker arm adjustment screw for the exhaust rocker arm

Adjust the valve lash while the engine is stopped.

1. Put the No. 1 piston at the top center position on the compression stroke. Refer to Testing and Adjusting, “Finding Top Center Position for No. 1 Piston”.
   

   Table 3

   TC Compression Stroke	Inlet Valves	Exhaust Valves
   Valve lash	0.38 ± 0.08 mm (0.015 ± 0.003 inch)	0.64 ± 0.08 mm (0.025 ± 0.003 inch)
   Cylinders	1-2-4	1-3-5

2. Adjust the valve lash according to Table 3.
   1. Lightly tap the rocker arm at the top of the adjustment screw with a soft mallet. This will ensure that the lifter roller seats against the camshaft’s base circle.
   2. Loosen the adjustment locknut.
   3. Place the appropriate feeler gauge between rocker arm and the valve bridge. Then, turn the adjustment screw in a clockwise direction. Slide the feeler gauge between the rocker arm and the valve bridge. Continue turning the adjustment screw until a slight drag is felt on the feeler gauge. Remove the feeler gauge.
   4. Tighten the adjustment locknut to a torque of 30 ± 7 N·m (22 ± 5 lb ft). Do not allow the adjustment screw to turn while you are tightening the adjustment locknut. Recheck the valve lash after tightening the adjustment locknut.

3. Remove the timing bolt and turn the flywheel by 360 degrees in the direction of engine rotation. This will put the No. 6 piston at the top center position on the compression stroke. Install the timing bolt in the flywheel.
   

   Table 4

   TC Exhaust Stroke (3)	Inlet Valves	Exhaust Valves
   Valve lash	0.38 ± 0.08 mm (0.015 ± 0.003 inch)	0.64 ± 0.08 mm (0.025 ± 0.003 inch)
   Cylinders	3-5-6	2-4-6

   ( 3 )

   Position for No. 1 cylinder

4. Adjust the valve lash according to Table 4.
   1. Lightly tap the rocker arm at the top of the adjustment screw with a soft mallet. This will ensure that the lifter roller seats against the camshaft’s base circle.
   2. Loosen the adjustment locknut.
   3. Place the appropriate feeler gauge between rocker arm and the valve bridge. Then, turn the adjustment screw in a clockwise direction. Slide the feeler gauge between the rocker arm and the valve bridge. Continue turning the adjustment screw until a slight drag is felt on the feeler gauge. Remove the feeler gauge.
   4. Tighten the adjustment locknut to a torque of 30 ± 7 N·m (22 ± 5 lb ft). Do not allow the adjustment screw to turn while you are tightening the adjustment locknut. Recheck the valve lash after tightening the adjustment locknut.

5. Remove the timing bolt from the flywheel after all adjustments to the valve lash have been made. Reinstall the timing cover.