C7.1 Engines and Generator Sets Caterpillar

Solenoid Valve - Test

Usage:

C7.1 770

This procedure covers the following diagnostic codes:

Show/hide table

Table 1
Diagnostic Codes for the Solenoid Valves
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
1076-5	18-5	Engine Fuel Injection Pump Fuel Control Valve : Current Below Normal	The Electronic Control Module (ECM) detects the following conditions: Low current in the output from the ECM to the fuel pump solenoid for 0.6 seconds There are no active 168 diagnostic codes. The ECM has been powered for at least 0.25 seconds. The warning lamp will come on. The ECM will log the diagnostic code. This diagnostic code detects a fault in the circuit for the fuel pump solenoid.
1076-6	18-6	Engine Fuel Injection Pump Fuel Control Valve : Current Above Normal	The ECM detects the following conditions: High current in the output from the ECM to the fuel pump solenoid for 0.6 seconds. There are no active 168 diagnostic codes. The ECM has been powered for at least 0.25 seconds. The warning lamp will come on. The ECM will log the diagnostic code. This diagnostic code detects a fault in the circuit for the fuel pump solenoid. This fault is most likely to be caused by a high side short to ground or a low side short to power.
1188-5	526-5	Engine Turbocharger 1 Wastegate Drive : Current Below Normal	The ECM detects the following conditions: A low current condition in the output from the ECM to the solenoid for the wastegate regulator. There are no active 168 diagnostic codes. The ECM has been powered for at least 2 seconds. The warning lamp will come on once the diagnostic code has been active for 30 seconds. The diagnostic code will be logged. The engine will be derated while this diagnostic code is active. After the engine derate has been activated, the electronic service tool will indicate "Turbo Protection Derate Active". This diagnostic code detects a fault in the wastegate regulator that is most likely to be an open circuit.
1188-6	526-6	Engine Turbocharger 1 Wastegate Drive : Current Above Normal	The ECM detects the following conditions: A high current condition in the output from the ECM to the solenoid in the wastegate regulator There are no active 168 diagnostic codes. The ECM has been powered for at least 2 seconds. The warning lamp will come on once the diagnostic code has been active for 30 seconds. The diagnostic code will be logged. The engine will be derated while this diagnostic code is active. After the engine derate has been activated, the electronic service tool will indicate "Turbo Protection Derate Active". This diagnostic code detects a fault in the circuit for the wastegate regulator. This fault is most likely to be caused by a high side short to ground or a low side short to power.
3479-5	2461-5	Aftertreatment #1 Fuel Pressure Control : Current Below Normal	The ECM detects the following conditions: A low current condition in the output from the ECM to the solenoid for the pilot fuel control valve on the Aftertreatment Regeneration Device (ARD) There are no active 678 diagnostic codes. The ECM has been powered for at least one second. The alert lamp will come on. The ECM will log the diagnostic code.
3479-6	2461-6	Aftertreatment #1 Fuel Pressure Control : Current Above Normal	The ECM detects the following conditions: A high current condition in the output from the ECM to the solenoid for the ARD pilot fuel control valve There are no active 678 diagnostic codes. The ECM has been powered for at least one second. The alert lamp will come on. The ECM will log the diagnostic code. The ECM will try to activate the control valve at 1 second intervals for 10 seconds. If the control valve does not activate, the ECM will disable the control valve until the keyswitch has been cycled.

The following background information is related to this procedure:

Electronically Controlled Wastegate

Show/hide table




Illustration 1	g03795243

The engine has a turbocharger with an electronically controlled wastegate (1). Typically, the wastegate is a mechanical valve that is used in the turbocharger to regulate the intake manifold pressure to a set value.

The control system for the electronically controlled wastegate precisely regulates the intake manifold pressure by using a wastegate regulator to control the wastegate.

The required intake manifold pressure is calculated by the software that is contained in the ECM. The ECM uses the wastegate regulator to control the wastegate to provide the precise value of intake manifold pressure. The solenoid in the wastegate regulator is controlled by a PWM signal from the ECM.

Suction Control Valve for the High-Pressure Fuel Pump

Show/hide table




Illustration 2	g03795285

The high-pressure fuel pump is equipped with a suction control valve (2). The suction control valve precisely controls the amount of fuel that enters the high-pressure fuel pump.

The amount of fuel that is required is calculated by the software that is contained in the ECM. The solenoid in the suction control valve is controlled by a PWM signal from the ECM.

ARD pilot fuel control valve

Show/hide table




Illustration 3	g06155963

The ARD pilot fuel control valve (3) controls the amount of fuel that is injected into the ARD when a DPF regeneration is taking place.

The amount of fuel that is required is calculated by the software that is contained in the ECM. The ARD pilot fuel control valve is controlled by a PWM signal from the ECM.

Show/hide table




Illustration 4	g06156003
Schematic for the solenoid valves

Show/hide table




Illustration 5	g01977637
Pin locations on the P2 connector for the solenoid valves (14) Wastegate regulator return (24) Wastegate regulator PWM signal (67) ARD pilot fuel control valve PWM signal (68) ARD pilot fuel control valve return (69) High-pressure fuel pump suction control valve PWM signal (70) High-pressure fuel pump suction control valve return

Show/hide table




Illustration 6	g01971875
Connector for the wastegate regulator (1) Return (2) Signal

Show/hide table




Illustration 7	g01976190
Connector for the ARD pilot fuel control valve (1) ARD pilot fuel control valve PWM signal (2) ARD pilot fuel control valve return

Complete the procedure in the order in which the steps are listed.

Show/hide table

Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Thoroughly inspect the terminal connections on the P2/J2 ECM connector and the solenoids. Refer to Troubleshooting, "Electrical Connectors - Inspect". B. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the solenoid connectors that are associated with the active diagnostic code. C. Check the screw for the ECM connector for the correct torque of 6 N·m (53 lb in). D. Check the harness for corrosion, abrasion, and pinch points from the solenoids to the ECM.	Loose connection or damaged wire	Result: There is a fault in a connector or the wiring. Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. Proceed to Test Step 2.
2. Check for Active 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. Wait at least 20 seconds for activation of the diagnostic codes. D. Verify if any of the diagnostic codes that are listed in Table 1 are active. E. Turn the keyswitch to the OFF position.	Diagnostic codes	Result: An XXXX-5 diagnostic code is active. Proceed to Test Step 3. Result: An XXXX-6 diagnostic is active. Proceed to Test Step 6.
3. Create a Short Circuit at the Harness Connector for the Solenoid A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the suspect solenoid. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Install the wire between the two pins on the harness connector for the suspect solenoid to create a short circuit. E. Turn the keyswitch to the ON position. Wait for 10 seconds. Check for active diagnostic codes on the electronic service tool. F. Remove the jumper wire from the connector for the solenoid valve.	Open circuit	Result: An XXXX-5 diagnostic code was active before installing the jumper. An XXXX-6 diagnostic code is active when the jumper is installed. There is a fault in the solenoid. Repair: Temporarily connect a replacement for the suspect valve to the harness. Turn the keyswitch to the ON position. Use the electronic service tool to check for active diagnostic codes. Wait at least 30 seconds in order for the codes to be displayed. If the fault is eliminated, reconnect the suspect valve. If the fault returns, permanently install the replacement valve. Refer to Disassembly and Assembly for the correct procedure. Result: A 3479-5 (2461-5) diagnostic code is still active with the jumper installed. Proceed to Test Step 4. Result: A 1076-5 (18-5) or 1188-5 (526-5) diagnostic code is still active with the jumper installed. Proceed to Test Step 9.
4. Create a Short Circuit at 40-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 40-pin connector. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Install the wire between the pin 21 and pin 22 on the 40-pin connector on the harness between the engine and the CEM. E. Turn the keyswitch to the ON position. Wait for 10 seconds. Check for active diagnostic codes on the electronic service tool. Note: While the 40-pin connector is disconnected, diagnostic codes for the other components that are connected to the 40-pin connector will be active. Disregard the diagnostic codes for all the other components. Only address the 3479 (2461) diagnostic codes. F. Remove the jumper wire.	Short circuit	Result: A 3479-5 (2461-5) diagnostic code was active before installing the jumper. A 3479-6 (2461-6) diagnostic code is active when the jumper is installed. The fault is in the CEM harness. Repair: Repair the faulty wiring or 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 3479-5 (2461-5) diagnostic code is still active with the jumper installed. Reconnect the 40-pin connector. Proceed to Test Step 5.
5. Create a Short Circuit at 31-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 31-pin connector. C. Fabricate a jumper wire that is 150 mm (6 inch) long. D. Install the wire between the pin 21 and pin 22 on the 31-pin connector on the harness between the engine and the CEM. E. Turn the keyswitch to the ON position. Wait for 10 seconds. Check for active diagnostic codes on the electronic service tool. Note: While the 31-pin connector is disconnected, diagnostic codes for the other components that are connected to the 31-pin connector will be active. Disregard the diagnostic codes for all the other components. Only address the 3479 (2461) diagnostic codes. F. Remove the jumper wire.	Short circuit	Result: A 3479-5 (2461-5) diagnostic code was active before installing the jumper. A 3479-6 (2461-6) diagnostic code is active when the jumper is installed. The fault is in the harness between the 31-pin connector and the 40-pin connector. Repair: Repair the faulty wiring or 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 3479-5 (2461-5) diagnostic code is still active with the jumper installed. Reconnect the 31-pin connector. Proceed to Test Step 9.
6. Create an Open Circuit at the Solenoid A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the suspect solenoid valve. C. Turn the keyswitch to the ON position. Wait for 10 seconds. Check for active diagnostic codes on the electronic service tool.	Short circuit	Result: An XXXX-6 diagnostic code was active before disconnecting the valve. An XXXX-5 diagnostic code is active with the valve disconnected. Repair: Temporarily connect a replacement for the suspect valve to the harness. Turn the keyswitch to the ON position. Use the electronic service tool to check for active diagnostic codes. Wait at least 30 seconds in order for the codes to be displayed. If the fault is eliminated, reconnect the suspect valve. If the fault returns, permanently install the replacement valve. Refer to Disassembly and Assembly for the correct procedure. Result: A 3479-6 (2461-6) diagnostic code is still active with the valve disconnected. Reconnect the ARD pilot fuel control valve. Proceed to Test Step 7. Result: A 1076-6 (18-6) or a 1188-5 (526-6) diagnostic code is still active with the valve disconnected. Proceed to Test Step 9.
7. Create an Open Circuit at 40-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 40-pin connector. C. Turn the keyswitch to the ON position. Wait for 10 seconds. Check for active diagnostic codes on the electronic service tool. Note: While the 40-pin connector is disconnected, diagnostic codes for the other components that are connected to the 40-pin connector will be active. Disregard the diagnostic codes for all the other components. Only address the 3479 (2461) diagnostic codes.	Open circuit	Result:A 3479-6 (2461-6) diagnostic code was active before disconnecting the 40-pin connector. A 3479-5 (2461-5) diagnostic code is active with the 40-pin connector disconnected. The fault is in the CEM harness. Repair: Repair the faulty wiring or 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 3479-6 (2461-6) diagnostic code is still active with the 40-pin connector disconnected. Reconnect the 40-pin connector. Proceed to Test Step 8.
8. Create an Open Circuit at 31-Pin Connector A. Turn the keyswitch to the OFF position. B. Disconnect the 31-pin connector. C. Turn the keyswitch to the ON position. Wait for 10 seconds. Check for active diagnostic codes on the electronic service tool. Note: While the 31-pin connector is disconnected, diagnostic codes for the other components that are connected to the 31-pin connector will be active. Disregard the diagnostic codes for all the other components. Only address the 3479 (2461) diagnostic codes.	Open circuit	Result:A 3479-6 (2461-6) diagnostic code was active before disconnecting the 31-pin connector. A 3479-5 (2461-5) diagnostic code is active with the 31-pin connector disconnected. The fault is in the harness between the 31-pin connector and the 40-pin connector. Repair: Repair the faulty wiring or 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 3479-6 (2461-6) diagnostic code is still active with the 31-pin connector disconnected. Reconnect the 40-pin connector. Proceed to Test Step 9.
9. Bypass the Engine Wiring Harness A. Turn the keyswitch to the OFF position. B. For a 1076 (18) or a 1188 (526) diagnostic code, perform Steps C. to I. For a 3479 (2461) diagnostic code, perform Steps J. to P. C. Disconnect the P2 connector and the connector for the suspect valve. D. Remove the signal wire and the return wire for the suspect valve from the P2 connector. E. Remove the signal wire and the return wire from the connector for the suspect valve. F. Fabricate two jumper wires that are long enough to reach from the ECM to the connector for the suspect valve. G. Insert one end of a jumper into the plug for the signal wire on the P2 connector. Insert the other end of the jumper into the plug for the signal wire on the connector for the suspect valve. H. Insert one end of the other jumper into the plug for the return wire on the P2 connector. Insert the other end of the jumper into the plug for the return wire on the connector for the suspect valve. I. Reconnect the P2 connector and the connector for the valve. Continue from Step Q. J. Disconnect the P2 connector and the 31-pin connector. K. Remove the wires from P2:67 and P2:68. L. Remove the wires from pins 21 and 22 on the 31-pin connector. M. Fabricate two jumper wires that are long enough to reach from the ECM to the 31-pin connector. N. Insert one end of a jumper into P2:67. Insert the other end of the jumper into socket 21 on the 31-pin connector. O. Insert one end of the other jumper into P2:68. Insert the other end of the jumper into socket 22 on the 31-pin connector. P. Reconnect the P2 connector and the 31-pin connector. Continue from Step Q. Q. Turn the keyswitch to the ON position. Wait for 10 seconds. R. Use the electronic service tool to monitor the "Active Diagnostic Code" screen. Check for either the open circuit diagnostic code for the suspect valve or the short circuit diagnostic code for the suspect valve. S. Remove the jumpers and reconnect the wires that were previously removed. T. Reconnect the connectors.	Harness bypass	Result: The diagnostic code disappears when the jumper is installed. There is a fault in the engine wiring harness. Repair: Repair the faulty harness or replace the faulty harness. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The diagnostic code is still present with the jumper installed. Contact the Dealer Solutions Network (DSN).