WASHER 6J9121 - Caterpillar

Perform this procedure if the following diagnostic code is active.
Table 1
J1939 Code and Description Comments
1392-13
Engine Air to Fuel Differential Pressure : Out of Calibration The calibration offset value for the fuel pressure is outside the acceptable range for the sensor.
The engine will not start.
The code is logged.
4817-13
Engine Intake Manifold #1 Absolute Pressure : Out of Calibration The calibration offset value for the fuel pressure is outside the acceptable range for the sensor.
The engine will not start.
The code is logged. Systems Operation
When the engine control is powered up, the Electronic Control Module (ECM) will verify that the calibration offset value is within the accepted range of −3 to 3 kPa ( 0.4351 psi). If the calibration offset value for the fuel pressure is outside the accepted range, the diagnostic code 1392-13 will be activated and the engine will not start.The diagnostic code is logged. The ECM does not need to be reset in order to clear the code. A valid calibration value will be required in order to operate the engine. The 1392-13 code will be cleared upon valid calibration.Procedure for Calibration of the "Air/Fuel Pressure Module"
Verify that the fuel shutoff valve is closed.
Turn the engine control switch to the STOP position.
Access the "Air Pressure Module Calibration" procedure in Cat® Electronic Technician (ET). This procedure is located under the "Service" pull-down menu under "Calibrations".
Open the ports to the air/fuel pressure module by disconnecting the air lines and the fuel lines from the pressure module. Ensure that the ports are open to atmospheric pressure.
Press the "OK" button in order to continue.
Press the next button in order to start the calibration procedure. Note: Wait for the next window in order to continue the calibration procedure.
The engine control switch must be in the STOP position.
The engine speed must be 0 rpm.
Enter the "Atmospheric Pressure Sensor Calibration Value". This value is the "Actual Air Pressure" that is shown on the Cat ET screen.
Press the "OK" button in order to continue.
If the calibration is a success, press the "Finish" button in order to complete the calibration procedure. Reconnect the air lines and the fuel lines to the pressure module and resume normal operation. Note: The ECM will perform the required measurement of the pressure in order to calculate the calibration offset value. This calibration offset value will be subtracted from all subsequent readings of the fuel differential pressure. If this value is greater than 3 kPa (0.4351 psi) or less than −3 kPa (−0.4351 psi), the calibration will fail and the ECM will not clear the 1392-13 active diagnostic code.
If the calibration fails, verify that both the air and the fuel ports of the pressure module are open to atmospheric pressure and repeat the calibration procedure. If the pressure module cannot be calibrated within the specification after three calibration attempts, the module must be replaced.