C7.1 Engines and Generator Sets Caterpillar

Sensor Signal (Analog, Active) - Test

Usage:

C7.1 770

This procedure covers the following diagnostic codes:

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Table 1
Diagnostic Codes for the Active Analog Sensors
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
100-3	100-3	Engine Oil Pressure : Voltage Above Normal	The Electronic Control Module (ECM) detects the following conditions: The signal voltage from the engine oil pressure sensor is greater than 4.8 VDC for more than 8 seconds. The warning lamp will come on. The ECM will log the diagnostic code. The ECM will set data for engine oil pressure to the default value. The default engine oil pressure is 600 kPa (87 psi). The electronic service tool will display "Voltage Above Normal" on the status screens.
100-4	100-4	Engine Oil Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage from the engine oil pressure sensor is less than 0.2 VDC for more than 8 seconds. The ECM has been powered for at least 2 seconds. The warning lamp will come on. The ECM will log the diagnostic code. The ECM will set data for the engine oil pressure to the default value. The default engine oil pressure is 600 kPa (87 psi). The electronic service tool will display "Voltage Below Normal" on the status screens.
108-3	3528-3	Barometric Pressure : Voltage Above Normal	The ECM detects the following conditions: The signal voltage for the barometric pressure sensor is greater than 4.8 VDC for at least 8 seconds. The warning lamp will come on. The ECM will log the diagnostic code.
108-4	3528-4	Barometric Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the barometric pressure sensor is less than 0.2 VDC for at least 8 seconds. The warning lamp will come on. The ECM will log the diagnostic code.
157-3	1797-3	Engine Injector Metering Rail #1 Pressure : Voltage Above Normal	The ECM detects the following conditions: The signal voltage for the fuel rail pressure sensor is more than 4.7 VDC for 0.6 seconds. The warning lamp will flash. The ECM will log the diagnostic code. The electronic service tool will display "70000 kPa" next to "Desired Fuel Rail Pressure" and "Actual Fuel Rail Pressure" on the status screens. The engine will be derated.
157-4	1797-4	Engine Injector Metering Rail #1 Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the fuel rail pressure sensor is less than 0.67 VDC for 0.6 seconds. The warning lamp will flash. The ECM will log the diagnostic code. The electronic service tool will display "70000 kPa" next to "Desired Fuel Rail Pressure" and "Actual Fuel Rail Pressure" on the status screens. The engine will be derated.
411-3	3387-3	Engine Exhaust Gas Recirculation Differential Pressure : Voltage Above Normal	The ECM detects the following conditions: The signal voltage for the NOx Reduction System (NRS) differential pressure sensor is more than 4.8 VDC. The ECM has been powered for at least 0.24 seconds. The warning light will come on. The ECM will log the diagnostic code.
411-4	3387-4	Engine Exhaust Gas Recirculation Differential Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the NRS differential pressure sensor is less than 0.2 VDC. The ECM has been powered for at least 0.24 seconds. The warning light will come on. The ECM will log the diagnostic code.
3241-3	535-3	Exhaust Gas Temperature 1 : Voltage Above Normal	The ECM detects the following conditions: The signal voltage for the ARD flame detection temperature sensor is greater than 4.7 VDC for at least 4 seconds. The ECM has been powered for at least 7 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code. The engine will be derated. If a DPF regeneration is in progress, the process will be stopped. Future regenerations will be prevented while the code is active.
3241-4	535-4	Exhaust Gas Temperature 1 : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the ARD flame detection temperature sensor is less than 0.3 VDC for at least 4 seconds. The ECM has been powered for at least 7 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code. The engine will be derated. If a DPF regeneration is in progress, the process will be stopped. Future regenerations will be prevented while the code is active.
3242-3	2452-3	Particulate Trap Intake Gas Temperature : Voltage Above Normal	The ECM detects the following conditions: The signal voltage for the DPF inlet temperature sensor is greater than 4.7 VDC for at least 4 seconds. The ECM has been powered for at least 7 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code. The engine will be derated. If a DPF regeneration is in progress, the process will be stopped. Future regenerations will be prevented while the code is active.
3242-4	2452-4	Particulate Trap Intake Gas Temperature : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the DPF inlet temperature sensor is less than 0.3 VDC for at least 4 seconds. The ECM has been powered for at least 7 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code. The engine will be derated. If a DPF regeneration is in progress, the process will be stopped. Future regenerations will be prevented while the code is active.
3358-3	3385-3	Engine Exhaust Gas Recirculation Inlet Pressure : Voltage Above Normal	The ECM detects the following conditions: The signal voltage from the NRS inlet pressure sensor is more than 4.8 VDC for 0.12 seconds. The ECM has been powered for 2 seconds. The warning light will come on. The ECM will log the diagnostic code. The ECM will set data for the NRS inlet pressure to the default value. The default value for the NRS inlet pressure is 250 kPa (36.3 psi).
3358-4	3385-4	Engine Exhaust Gas Recirculation Inlet Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the NRS inlet pressure sensor is less than 0.2 VDC for 0.12 seconds. The ECM has been powered for 2 seconds. The warning light will come on. The ECM will log the diagnostic code. The ECM will set data for the NRS inlet pressure to the default value. The default value for the NRS inlet pressure is 250 kPa (36.3 psi).
3480-3	2460-3	Aftertreatment #1 Fuel Pressure #1 : Voltage Above Normal	The ECM detects the following conditions: The signal voltage for the Aftertreatment Regeneration Device (ARD) pilot fuel pressure sensor is greater than 4.7 VDC for at least 2 seconds. The warning light will come on. The ECM will log the diagnostic code. The engine will be derated. If a DPF regeneration is in progress, the process will be stopped. Future regenerations will be prevented while the code is active.
3480-4	2460-4	Aftertreatment #1 Fuel Pressure #1 : Voltage Below Normal	The ECM detects the following conditions: The signal voltage for the ARD pilot fuel pressure sensor is less than 0.2 VDC for 0.12 seconds. The warning light will come on. The ECM will log the diagnostic code. The engine will be derated. If a DPF regeneration is in progress, the process will be stopped. Future regenerations will be prevented while the code is active.
3563-3	1785-3	Engine Intake Manifold #1 Absolute Pressure : Voltage Above Normal	The ECM detects the following conditions: The signal voltage from the intake manifold pressure sensor is above 4.8 VDC for at least 8 seconds. The ECM has been powered for 2 seconds. The warning light will come on. The ECM will log the diagnostic code. The data for the intake manifold pressure will be set to a maximum valid pressure for 2 seconds. The ECM will then flag the intake manifold pressure as being invalid. A default value is then used for the intake manifold pressure. The current for the wastegate regulator will be set to a default value while this code is active. This condition will cause the engine to have poor acceleration. The default setting will prevent any overpressure in the intake manifold which could be caused by an overspeed of the turbocharger.
3563-4	1785-4	Engine Intake Manifold #1 Absolute Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage from the intake manifold pressure sensor is less than 0.2 VDC for at least 8 seconds. The ECM has been powered for 2 seconds. The warning light will come on. The ECM will log the diagnostic code. The data for the intake manifold pressure will be set to a maximum valid pressure for 2 seconds. The ECM will then flag the intake manifold pressure as being invalid. A default value is then used for intake manifold pressure. The current for the wastegate regulator will be set to a default value while this code is active. This condition will cause the engine to have poor acceleration. The default setting will prevent any overpressure in the intake manifold which could be caused by an overspeed of the turbocharger.
3609-3	3464-3	Diesel Particulate Filter Intake Pressure 1 : Voltage Above Normal	The ECM detects the following conditions: The signal voltage from the DPF inlet pressure sensor is more than 4.95 VDC. The ECM has been powered for at least 0.24 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code.
3609-4	3464-4	Diesel Particulate Filter Intake Pressure 1 : Voltage Below Normal	The ECM detects the following conditions: The signal voltage from the DPF inlet pressure sensor is less than 0.2 VDC. The ECM has been powered for at least 0.24 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code.
3837-3	3493-3	Aftertreatment 1 Secondary Air Pressure : Voltage Above Normal	The ECM detects the following conditions: The signal voltage from the ARD air pressure sensor is more than 4.8 VDC. The ECM has been powered for at least 0.24 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code.
3837-4	3493-4	Aftertreatment 1 Secondary Air Pressure : Voltage Below Normal	The ECM detects the following conditions: The signal voltage from the ARD air pressure sensor is less than 0.2 VDC. The ECM has been powered for at least 0.24 seconds. If equipped, the warning light will come on. The ECM will log the diagnostic code.

The following conditions must exist before any of the above codes will become active:

There are no active 3509 (262) codes.
There are no active 168 codes.

The following background information is related to this procedure:

The 5 VDC sensor supply provides power to all 5 VDC sensors. The ECM supplies 5 VDC to terminal "3" of the fuel rail pressure sensor connector and to terminal "1" of all other active sensor connectors. The sensor common from the ECM connector goes to terminal "1" of the connector for the fuel rail pressure sensor. The sensor common from the ECM connector goes to terminal "2" of all other active sensor connectors. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.

Pull-up Voltage

The ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage to detect an open in the signal circuit. When the ECM detects a voltage above a threshold on the signal circuit, an open circuit diagnostic code (XXXX-3) is generated for the sensor.

If the sensor is disconnected, pull-up voltage indicates that the wires from the sensor connector to the ECM are not open or shorted to ground. If the sensor is disconnected, the absence of pull-up voltage indicates an open in the signal wire or a short to ground. If the sensor is disconnected and the voltage is different from pull-up voltage, the signal wire is shorted to another wire in the harness.

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Illustration 1	g06154535
Schematic for the active sensors

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Illustration 2	g06154552
Typical view of the pin locations on the P2 connector for the pressure sensors (4) Intake manifold pressure sensor signal (5) DPF inlet pressure sensor signal (6) NRS inlet pressure sensor signal (7) NRS differential pressure sensor signal (17) DPF inlet temperature sensor signal (25) ARD air pressure sensor signal (26) ARD pilot fuel pressure signal sensor (27) DPF differential pressure sensor signal (33) ARD flame detection temperature sensor signal (34) Barometric pressure sensor signal (35) Oil pressure sensor signal (37) Fuel rail pressure sensor signal (45) Clean Emissions Module (CEM) pressure sensors 5 VDC supply (46) Oil pressure sensor 5 VDC supply (47) Engine pressure sensors 5 VDC supply (55) CEM pressure sensors ground (56) Oil pressure sensor ground (57) Engine pressure sensors ground

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Illustration 3	g06154546
Typical view of the pin locations for the pressure sensors on the connectors from the engine to the CEM (1) CEM pressure sensors 5 VDC supply (2) CEM pressure sensors ground (4) DPF inlet pressure sensor signal (5) ARD flame detection temperature signal (6) DPR inlet temperature signal (7) DPF differential pressure sensor signal (8) ARD air pressure sensor signal (20) ARD pilot fuel pressure sensor signal

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Illustration 4	g01170309
Fuel rail pressure sensor (1) Ground (2) Signal (3) 5 VDC Supply

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Illustration 5	g01170310
Typical example of an engine pressure sensor (1) 5 VDC Supply (2) Ground (3) Signal

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Illustration 6	g02177603
Typical example of the connector for the DPF inlet/ARD flame detection temperature sensor (1) 5 VDC supply (2) Ground (3) ARD flame detection temperature sensor signal (4) DPF inlet temperature sensor signal

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

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Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Thoroughly inspect the terminal connections on the P2/J2 ECM connectors and the engine pressure sensors. 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 sensor 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 engine pressure sensors 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 10 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: There are no active diagnostic codes for the active sensors. Repair: If there are logged diagnostic codes for the active sensors, the fault may be intermittent. Refer to Troubleshooting, "Electrical Connectors - Inspect" to identify intermittent faults. Result: A diagnostic code that is listed in Table 1 is active. Proceed to Test Step 3.
3. Check the Supply Voltage at the Sensor Connector A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the suspect sensor. C. Turn the keyswitch to the ON position. Do not start the engine. D. Measure the voltage between the supply terminal and the ground terminal on the harness connector for the suspect sensor. E. Turn the keyswitch to the OFF position. F. Reconnect the sensor.	4.8 VDC to 5.2 VDC	Result: The voltage measurement is not within the expected range. If the suspect sensor is not on the CEM, the fault is in the supply wire or the ground wire in the engine wiring harness. Repair: Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service. Result: The voltage measurement is not within the expected range. The suspect sensor is on the CEM. Proceed to Test Step 4. Result: The voltage measurement is within the expected range. The correct supply voltage is reaching the sensor. Proceed to Test Step 6.
4. Check the Supply Voltage at the 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. Do not start the engine. D. Measure the voltage between pin 1 and pin 2 on the 40-pin connector on the harness between the engine and the CEM. E. Turn the keyswitch to the OFF position. F. Reconnect the sensor.	4.8 VDC to 5.2 VDC	Result: The voltage measurement is within the expected range. The fault is in the CEM harness between the 40-pin connector and the sensor connector. Repair: Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service. Result: The voltage measurement is not within the expected range. The correct voltage is not reaching the 40-pin connector. Proceed to Test Step 5.
5. Check the Supply Voltage at the 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. Do not start the engine. D. Measure the voltage between pin 1 and pin 2 on the 31-pin connector on the engine harness. E. Turn the keyswitch to the OFF position. F. Reconnect the sensor.	4.8 VDC to 5.2 VDC	Result: The voltage measurement is within the expected range. The fault is in the CEM harness between the 40-pin connector and the 31-pin connector. Repair: Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service. Result: The voltage measurement is not within the expected range. The correct voltage is not reaching the 31-pin connector. Repair: Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service.
6. Check the Type of Diagnostic Code that is Active A. Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes. B. Use the electronic service tool to check for active diagnostic codes. Record all active diagnostic codes.	Diagnostic codes	Result: An XXXX-4 diagnostic code is active for one or more of the active sensors. Proceed to Test Step 7. Result: An XXXX-3 diagnostic code is active for one or more of the active sensors. Proceed to Test Step 10.
7. Create An Open Circuit at the Sensor Connector A. Turn the keyswitch to the OFF position. B. Disconnect the connector for the sensor with the XXXX-4 diagnostic code. C. Turn the keyswitch to the ON position. Wait for at least 10 seconds for activation of the diagnostic codes. D. Use the electronic service tool to check the "Active Diagnostic Code" screen. Check for an XXXX-3 diagnostic code.	Diagnostic codes	Result: An XXXX-4 diagnostic code was active before disconnecting the sensor. An XXXX-3 diagnostic code became active after disconnecting the sensor. The sensor is faulty. Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Use the electronic service tool to verify that the repair eliminates the fault and then permanently install the new sensor. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The XXXX-4 diagnostic code is still active. If the suspect sensor is on the CEM, proceed to Test Step 8. Proceed to Test Step 6.
8. Create an Open Circuit at the 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 at least 10 seconds for activation of the diagnostic codes. 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 diagnostic codes for the suspect sensor. D. Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active XXXX-3 diagnostic code for the suspect sensor. E. Turn the keyswitch to the OFF position. F. Reconnect the 40-pin connector.	Open circuit	Result: An XXXX-4 diagnostic code was active before disconnecting the 40-pin connector. An XXXX-3 diagnostic code for the suspect sensor became active after the 40-pin connector was 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. Return the engine to service. Result: The XXXX-4 diagnostic code is still present. Proceed to Test Step 9.
9. Create an Open Circuit at the 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 at least 10 seconds for activation of the diagnostic codes. 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 diagnostic codes for the suspect sensor. D. Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active XXXX-3 diagnostic code for the suspect sensor. E. Turn the keyswitch to the OFF position. F. Reconnect the 31-pin connector.	Open circuit	Result: An XXXX-4 diagnostic code was active before disconnecting the 31-pin connector. An XXXX-3 diagnostic code for the suspect sensor became active after the 31-pin connector was disconnected. The fault is in the harness between the 40-pin connector and the 31-pin connector. Repair: Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service. Result: The XXXX-4 diagnostic code is still present. Proceed to Test Step 13.
10. Create a Short Circuit at the Sensor Connector A. Turn the keyswitch to the OFF position. B. Disconnect the connector from the suspect sensor. C. Fabricate a jumper wire that is 150 mm (6 inch) long. Crimp a terminal to both ends of the wire. D. Use the jumper to connect the sensor signal terminal to the sensor ground terminal on the harness connector for the suspect sensor. E. Turn the keyswitch to the ON position. Do not start the engine. F. Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active XXXX-4 diagnostic code for the suspect sensor. G. Turn the keyswitch to the OFF position. H. Remove the jumper. Reconnect the sensor.	Short circuit	Result: An XXXX-3 diagnostic code was active before installing the jumper. An XXXX-4 diagnostic code became active with the jumper installed. There may be a fault in the sensor. Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Use the electronic service tool to verify that the repair eliminates the fault and then permanently install the new sensor. Use the electronic service tool to clear all logged diagnostic codes. Result: The XXXX-3 diagnostic code remains active when the jumper is installed. If the suspect sensor is on the CEM, proceed to Test Step 11. If the suspect sensor is not on the CEM, proceed to Test Step 13.
11. Create a Short Circuit at the 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. Crimp a terminal to both ends of the wire. D. Use the jumper to connect the sensor signal terminal to the sensor ground terminal on the harness between the engine and the CEM. E. Turn the keyswitch to the ON position. Do not start the engine. F. Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active XXXX-4 diagnostic code for the suspect sensor. G. Remove the jumper. Reconnect the 40-pin connector.	Short circuit	Result: An XXXX-3 diagnostic code was active before installing the jumper. An XXXX-4 diagnostic code became active with the jumper installed. The fault is in the CEM harness between the sensor 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: The XXXX-3 diagnostic code remains active when the jumper is installed. Proceed to Test Step 12.
12. Create a Short Circuit at the 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. Crimp a terminal to both ends of the wire. D. Use the jumper to connect the sensor signal terminal to the sensor ground terminal on the engine harness. E. Turn the keyswitch to the ON position. Do not start the engine. F. Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active XXXX-4 diagnostic code for the suspect sensor. G. Remove the jumper. Reconnect the 31-pin connector.	Short circuit	Result: An XXXX-3 diagnostic code was active before installing the jumper. An XXXX-4 diagnostic code became active with the jumper installed. The fault is in the harness between the 40-pin connector and the 31-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: The XXXX-3 diagnostic code remains active when the jumper is installed. Proceed to Test Step 13.
13. Bypass the Signal Wire in the Engine Harness A. Turn the keyswitch to the OFF position. B. If the suspect sensor is on the CEM, perform Steps C. to G. If the suspect sensor is not on the CEM, perform Steps H. onwards. C. Disconnect the P2 connector. Disconnect the 31-pin connector. D. Remove the signal wire for the suspect sensor from the P2 connector. Remove the signal wire for the suspect sensor from the 31-pin connector on the engine harness. E. Fabricate a jumper wire that is long enough to reach from the ECM to the 31-pin connector. F. Insert one end of the jumper wire into the socket for the suspect sensor signal on the 31-pin connector on the engine harness. Insert the other end of the jumper wire into the socket for the suspect sensor signal on the P2 connector. G. Reconnect the P2 connector. Reconnect the 31-pin connector. Continue from Step M. H. Disconnect the P2 connector and disconnect the connector from the suspect sensor. I. Remove the sensor signal wire from the P2 connector. Remove the signal wire from the suspect sensor connector on the engine harness. J. Fabricate a jumper wire that is long enough to reach from the ECM to the sensor connector. K. Insert one end of the jumper wire into the signal terminal on the suspect sensor connector on the engine harness. Insert the other end of the jumper wire into the signal socket for the suspect sensor on the P2 connector. L. Reconnect the P2 connector. Reconnect the connector for the suspect sensor. M. Turn the keyswitch to the ON position. Do not start the engine. N. Access the "Active Diagnostic Codes" screen on the electronic service tool and check for active diagnostic codes for the suspect sensor. O. Turn the keyswitch to the OFF position. P. Return the wiring to the original configuration.	Bypass wiring	Result: There are no active diagnostic codes for the suspect sensor. The fault is in the engine 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: There is still an active diagnostic code for the suspect sensor. Contact the Dealer Solutions Network (DSN).