C3.4B Engines Caterpillar

Motorized Valve - Test

Usage:

CCS7 4B2

This procedure covers the following codes:

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Table 1
Diagnostic Trouble Codes for the Motorized Valves
J1939 Code	Description	Notes
2791-5	Engine Exhaust Gas Recirculation (EGR) Valve Control : Current Below Normal	The Electronic Control Module (ECM) detects the following conditions: A low current condition in the output for the Exhaust Gas Recirculation (EGR) valve for at least 0.6 seconds. The battery voltage is at least 10 VDC. The warning lamp will flash. The engine will be derated.
2791-6	Engine Exhaust Gas Recirculation (EGR) Valve Control : Current Above Normal	The ECM detects the following conditions: A high current condition in the output for the EGR valve for at least 0.6 seconds. The battery voltage is at least 10 VDC. The warning lamp will flash. The engine will be derated.
2791-7	Engine Exhaust Gas Recirculation (EGR) Valve Control : Not Responding Properly	The ECM detects the following conditions: The signal from the EGR valve position sensor indicates that the valve is not in the desired position. This diagnostic code can be caused by a loss of the 5 VDC supply to the EGR valve position sensor. The warning lamp will flash. The engine will be derated.
5419-5	Engine Throttle Actuator #1 : Current Below Normal	The ECM detects the following conditions: A low current condition in the output for the engine intake throttle valve for at least 0.6 seconds. The warning lamp will come on.
5419-6	Engine Throttle Actuator #1 : Current Above Normal	The ECM detects the following conditions: A high current condition in the output for the engine intake throttle valve for at least 1 second. The warning lamp will come on.
5419-7	Engine Throttle Actuator #1 : Not Responding Properly	The ECM detects the following conditions: The signal from the intake throttle valve position sensor indicates that the valve is not in the desired position. This diagnostic code can be caused by a loss of the 5 VDC supply to the intake throttle valve position sensor. The engine will be derated. The ECM will log the diagnostic code.

The following background information is related to this procedure:

EGR Valve

The EGR valve is used to control the amount of exhaust gas which is recirculated into the intake manifold.

The amount of exhaust gas that is required is calculated by the software that is contained in the ECM. The EGR valve is controlled by a PWM signal from the ECM.

Intake Throttle Valve

The intake throttle valve is used to increase the exhaust gas temperature to aid the regeneration process.

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Illustration 1	g03728445
Schematic diagram for the motorized valves

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Illustration 2	g03728447
Typical view of the pin locations on the 62-pin engine interface connector for the motorized valves (29) EGR valve PWM signal (30) EGR valve return (33) EGR valve position sensor 5 VDC supply (34) EGR valve position sensor signal (35) EGR valve position sensor ground (37) Intake throttle valve PWM signal (38) Intake throttle valve return (41) Intake throttle valve position sensor 5 VDC supply (42) Intake throttle valve position sensor signal (43) Intake throttle valve position sensor ground

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Illustration 3	g03616849
Typical view of the pin locations on the J2 connector for the motorized valves. (8) Intake throttle valve position sensor 5 VDC supply (9) EGR valve position sensor 5 VDC supply (24) EGR valve position sensor ground (34) Intake throttle valve return (35) EGR valve return (37) Intake throttle valve position sensor ground (39) EGR valve position sensor signal (49) Intake throttle valve PWM signal (50) EGR valve PWM signal (53) Engine intake throttle valve position sensor signal

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Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Thoroughly inspect connectors for the motorized valves. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. B. Thoroughly inspect the P2/J2 ECM connector and the 62-pin engine interface connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. C. Perform a 30 N (6.7 lb) pull test on each of the wires that are associated with the motorized valves.	Damaged wire or connector	Result: A damaged wire or damaged connector was found. Repair: Repair the damaged wire or the damaged connector. Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault. Result: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion or of pinch points. Proceed to Test Step 2.
2. Check for Diagnostic Codes A. Turn the keyswitch to the OFF position. B. Connect the electronic service tool to the diagnostic connector. C. Turn the keyswitch to the ON position. D. Monitor the electronic service tool for active diagnostic codes and/or logged diagnostic codes.	Diagnostic codes	Result: A -7 diagnostic code is active or recently logged for one or more of the motorized valves Proceed to Test Step 3. Result: A -5 diagnostic code is active or recently logged for one or more of the motorized valves. Proceed to Test Step 5. Result: A -6 diagnostic code is active or recently logged for one or more of the motorized valves. Proceed to Test Step 8.
3. Measure the Sensor Supply Voltage at the Valve Connector A. Turn the keyswitch to the OFF position. B. Disconnect the suspect valve from the engine harness. C. Turn the keyswitch to the ON position. D. Measure the voltage at the harness connector for the valve from the 5 V supply terminal of the position sensor to the sensor ground terminal.	4.9 v to 5.1 V	Result: The measured voltage is within the expected range. Repair: Install a replacement for the suspect valve. Refer to Disassembly and Assembly for more information. Note: If the EGR valve is replaced, use the electronic service tool to perform the "EGR Valve Learn Reset". Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault. Result: The measured voltage is not within the expected range. Reconnect the valve connector. Proceed to Test Step 4.
4. Measure the Sensor Supply Voltage at the 62-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 62-pin connector. C. Turn the keyswitch to the ON position. D. Measure the voltage at the 62-pin connector on the harness between the engine and the ECM from the 5 VDC sensor supply terminal for the suspect valve to the sensor ground terminal .	4.9 V to 5.1 V	Result: The measured voltage is within the expected range. The fault is in the 5 VDC supply wire or the ground wire between the suspect valve and the 62-pin connector. Repair: Replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The measured voltage is not within the expected range. The fault is in the 5 VDC supply wire or the ground wire between the ECM and the 62-pin connector. Repair: Replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
5. Create a Short Circuit at the Valve Connector A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the suspect valve. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Install the jumper between the PWM signal and return pins on the connector for the suspect valve in order to create a short circuit. E. Turn the keyswitch to the ON position. Check for active diagnostic codes on the electronic service tool. F. Turn the keyswitch to the OFF position. G. Remove the jumper wire.	Diagnostic codes	Result: A -6 is active with the jumper installed. Repair: Reconnect the valve. Start the engine. Check for active diagnostic codes on the electronic service tool. Wait at least 30 seconds in order for the codes to be displayed. If the -5 diagnostic code returns, then replace the valve. Refer to Disassembly and Assembly for the correct procedure. Note: If the EGR valve is replaced, use the electronic service tool to perform the "EGR Valve Learn Reset". Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: A -5 diagnostic code is still active with the jumper installed. Proceed to Test Step 6.
6. Create a Short Circuit at the 62-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 62-pin connector. C. Fabricate a jumper wire that is 150 mm (6 inch) long. Install the jumper wire between the PWM supply and return terminals for the suspect valve on the 62-pin connector on the harness between the engine and the ECM. D. Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes. Note: Diagnostic codes for all of the engine sensors will be active with the 62-pin connector disconnected. Ignore all other diagnostic codes and only look for codes that relate to the suspect valve. E. Look for an active -6 diagnostic code for the suspect valve. F. Remove the jumper wire.	Diagnostic codes	Result: A -6 diagnostic code is active when the jumper is installed. The fault is in the PWM supply wire or the return wire between the suspect valve and the 62-pin connector. Repair: Replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: A -5 diagnostic code is still active with the jumper installed. Proceed to Test Step 7.
7. Create a Short Circuit at the ECM Connector A. Turn the keyswitch to the OFF position. B. Disconnect the P2 connector from the ECM. C. Fabricate a jumper wire that is 150 mm (6 inch) long. Install the jumper wire between the PWM supply wire and the return wire for the suspect valve on the J2 connector. D. Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes. Note: Diagnostic codes for all of the engine sensors will be active with the P2 connector disconnected. Ignore all other codes and only look for codes that relate to the suspect valve. E. Look for an active -6 diagnostic code for the suspect valve. F. Turn the keyswitch to the OFF position.	Diagnostic codes	Result: A -6 diagnostic code was active with the jumper installed. The fault is in the wiring between the 62-pin engine interface connector and the ECM. Repair: Replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: A -5 diagnostic code is still active with the jumper installed. Contact the Dealer Solution Network (DSN).
8. Create an Open Circuit at the Valve Connector A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the suspect valve in order to create an open circuit. C. Turn the keyswitch to the ON position. Check for active diagnostic codes on the electronic service tool. Wait at least 30 seconds in order for the codes to be displayed.	Diagnostic Codes	Result: A -5 diagnostic code is active with the valve disconnected. Repair: Reconnect the valve. Start the engine. Check for active diagnostic codes on the electronic service tool. Wait at least 30 seconds in order for the codes to be displayed. If the -6 diagnostic code returns, then replace the valve. Refer to Disassembly and Assembly for the correct procedure. Note: If the EGR valve is replaced, use the electronic service tool to perform the "EGR Valve Learn Reset". When the reset is complete, operate the engine until the engine coolant temperature is greater than 60° C (140° F). Turn the keyswitch to the OFF position and wait for 2 minutes or until the "Wait to Disconnect" indicator (if installed) switches off . Turn the keyswitch to the ON position. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: A -6 diagnostic code is still active with the valve disconnected. Proceed to Test Step 9.
9. Create an Open Circuit at the 62-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 62-pin connector. C. Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes. Note: Diagnostic codes for all of the engine sensors will be active with the 62-pin connector disconnected. Ignore all other codes and only look for codes that relate to the suspect valve. D. Check for an active -5 diagnostic code for the suspect valve. E. Turn the keyswitch to the OFF position.	Diagnostic codes	Result: A -5 diagnostic code is active with the 62-pin connector disconnected. The fault is in the wiring between the suspect valve and the 62-pin connector. Repair: Replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: A -6 diagnostic code is still active with the 62-pin connector disconnected. Proceed to Test Step 10.
10. Create an Open Circuit at the ECM Connector A. Turn the keyswitch to the OFF position. B. Disconnect the P2 connector. C. Turn the keyswitch to the ON position. Wait at least 30 seconds for activation of the diagnostic codes. Note: Diagnostic codes for all of the engine sensors will be active with the P2 connector disconnected. Ignore all other diagnostic codes and only look for codes that relate to the suspect valve. D. Check for an active -5 diagnostic code for the suspect valve.	Diagnostic codes	Result: A -5 diagnostic code is active with the P2 connector disconnected. The fault is in the wiring between the suspect valve and the ECM P2 connector. Repair: Replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: A -6 diagnostic code is still active with the P2 connector disconnected. Contact the Dealer Solution Network (DSN).