C7.1 Industrial Engine and Generator Set Caterpillar

Sensor Calibration Required - Test

Usage:

C7.1 770

System Operation Description:

Use this procedure to troubleshoot a fault with a pressure sensor calibration. Also, use this procedure if any one of the diagnostic codes in Table 1 is active or easily repeated.

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Table 1
Diagnostic Codes Table
J1939 Code	Code Description	Comments
411-13	Engine Exhaust Gas Recirculation Differential Pressure : Out of Calibration	During calibration, the pressure offset must be within 5 kPa (0.7 psi) of 0 kPa (0.0 psi). During calibration, the pressure offset value is outside the acceptable range. The code is logged.
3358-13	Engine Exhaust Gas Recirculation Inlet Pressure : Out of Calibration	During calibration, the pressure offset must be within 15 kPa (2.2 psi) of the barometric pressure sensor. During calibration, the pressure offset value is outside the acceptable range. The code is logged.
3563-13	Engine Intake Manifold #1 Absolute Pressure : Out of Calibration	During calibration, the pressure offset must be within 15 kPa (2.2 psi) of the barometric pressure sensor. During calibration, the pressure offset value is outside the acceptable range. The code is logged.
3609-13	DPF #1 Intake Pressure : Out of Calibration	During calibration, the pressure offset must be within 15 kPa (2.2 psi) of the barometric pressure sensor. During calibration, the pressure offset value is outside the acceptable range. The code is logged.
3837-13	Aftertreatment 1 Secondary Air Pressure : Out of Calibration	During calibration, the pressure offset must be within 15 kPa (2.2 psi) of the barometric pressure sensor. During calibration, the pressure offset value is outside the acceptable range. The code is logged.

The Electronic Control Module (ECM) checks the signals from certain pressure sensors 12 seconds after the keyswitch is turned to the OFF position. The key must remain in the OFF position for a further 2 seconds in order for the ECM to check the signals from the sensors. During this time, the ECM compares the signal from the barometric pressure sensor with the signal from the following pressure sensors:

Intake manifold air pressure
NRS inlet pressure
DPF intake pressure
ARD combustion air pressure

The sensor signal must be within the specified range of the signal from the reference pressure sensor. If, a sensor signal is out of the range the corresponding fault code becomes active.

The NRS differential pressure sensor will calibrate to zero differential pressure.

The offset value is stored in the engine ECM. If the requirements are not met for the offset to be checked against the barometric pressure sensor, the stored value is used.

Test Step 1. Check for Diagnostic Codes

Establish communication between the electronic service tool and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
Download the "Product Summary Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
Wait at least 30 seconds in order for the diagnostic codes to become active.
Look for an active -13 code or for a logged -13 code.

Results:

There is an active or there is a logged -13 code for only one sensor. - Proceed to Test Step 2.
There is an active or there is a logged -13 code for more than one sensor. - Proceed to Test Step 3.

Test Step 2. Inspect the Suspect Sensor Connector

Turn the keyswitch to the OFF position.
Inspect the connector of the suspect sensor. Verify that there is no moisture.
Turn the keyswitch to the ON position.
Monitor the status parameter for the suspect sensor on the electronic service tool. Wiggle the wiring at the suspect sensor connector.

Results:

The value of the status parameter does not remain steady. -
Repair: Perform the following procedure.
1. Disconnect the suspect sensor connector.
2. Remove any moisture from the outside of the connector. Check for moisture and corrosion inside the connector. Verify that the seals for the wires are sealing correctly. Refer to Troubleshooting, "Electrical Connectors - Inspect", if necessary.
3. If necessary, repair the connector or replace the connector.
4. Reconnect the connector. Verify that the connection is secure.
5. Monitor the status parameter for the suspect sensor on the electronic service tool. Wiggle the wiring at the suspect sensor connector. Verify that the signal is steady.
6. Turn the keyswitch to the OFF position. Clear the -13 diagnostic code. Wait for 20 seconds for the calibration to complete.
7. Turn the keyswitch to the ON position.
8. Monitor the diagnostic codes on the electronic service tool. Check for an active -13 diagnostic code for the suspect sensor.
  Wait at least 30 seconds in order for the diagnostic codes to become active.
9. If the -13 code is active, replace the sensor. Verify that the fault is eliminated.
STOP
The value of the status parameter remains steady. -
Repair: Perform the following procedure.
1. Disconnect the suspect sensor connector.
2. Check for corrosion inside the connector. Verify that the seals for the wires are sealing correctly. Refer to Troubleshooting, "Electrical Connectors - Inspect", if necessary.
3. If necessary, repair the connector or replace the connector.
4. Reconnect the connector. Verify that the connection is secure.
5. Monitor the status parameter for the suspect sensor on the electronic service tool. Wiggle the wiring at the suspect sensor connector. Verify that the signal is steady.
6. Turn the keyswitch to the OFF position. Clear the -13 diagnostic code. Wait for 20 seconds for the calibration to complete.
7. Turn the keyswitch to the ON position.
8. Monitor the diagnostic codes on the electronic service tool. Check for an active -13 diagnostic code for the suspect sensor.
  Wait at least 30 seconds in order for the diagnostic codes to become active.
9. If the -13 code is active, replace the sensor. Verify that the fault is eliminated.
STOP

Test Step 3. Inspect the Connector for the Barometric Pressure Sensor

Turn the keyswitch to the OFF position.
Inspect the connector of the barometric pressure sensor. Verify that there is no moisture.
Turn the keyswitch to the ON position.
Monitor the status parameter for the barometric pressure sensor on the electronic service tool. Wiggle the wiring at the sensor connector.

Results:

The value of the status parameter does not remain steady. -
Repair: Perform the following procedure.
1. Disconnect the connector from the barometric pressure sensor.
2. Remove any moisture from the outside of the connector. Check for moisture and corrosion inside the connector. Verify that the seals for the wires are sealing correctly. Refer to Troubleshooting, "Electrical Connectors - Inspect", if necessary.
3. If necessary, repair the connector or replace the connector.
4. Reconnect the connector. Verify that the connection is secure.
5. Monitor the status parameter for the barometric pressure sensor on the electronic service tool. Wiggle the wiring at the connector for the barometric pressure sensor . Verify that the signal is steady.
6. Turn the keyswitch to the OFF position. Clear the -13 diagnostic codes. Wait for 20 seconds for the calibration to complete.
7. Turn the keyswitch to the ON position.
8. Monitor the diagnostic codes on the electronic service tool. Check for active -13 diagnostic codes.
  Wait at least 30 seconds in order for the diagnostic codes to become active.
9. If more than one -13 code is active, replace the barometric pressure sensor. Verify that the fault is eliminated.
STOP
The value of the status parameter remains steady. -
Repair: Perform the following procedure.
1. Disconnect the connector from the barometric pressure sensor.
2. Check for corrosion inside the connector. Verify that the seals for the wires are sealing correctly. Refer to Troubleshooting, "Electrical Connectors - Inspect", if necessary.
3. If necessary, repair the connector or replace the connector.
4. Reconnect the connector. Verify that the connection is secure.
5. Monitor the status parameter for the suspect reference sensor on the electronic service tool. Wiggle the wiring at the connector for the barometric pressure sensor . Verify that the signal is steady.
6. Turn the keyswitch to the OFF position. Clear the -13 diagnostic codes. Wait for 20 seconds for the calibration to complete.
7. Turn the keyswitch to the ON position.
8. Monitor the diagnostic codes on the electronic service tool. Check for active -13 diagnostic codes.
  Wait at least 30 seconds in order for the diagnostic codes to become active.
9. If more than one -13 code is active, replace the barometric pressure sensor. Verify that the fault is eliminated.
STOP