0308995 JOHNSON SCREW, Mount motor cover

Table 1
Diagnostic Trouble Codes
CDL Code and Description Conditions which Generate the Code System Response
41-3 8 Volt DC Supply : Voltage Above Normal The Electronic Control Module (ECM) has detected a voltage that is above normal in the 8 V supply circuit. The code is logged.
The digital sensor is set to the default value.
41-4 8 Volt DC Supply : Voltage Below Normal The ECM has detected a voltage that is below normal in the 8 V supply circuit.
262-3 5 Volt Sensor DC Power Supply : Voltage Above Normal The ECM has detected a voltage that is above normal in the 5 V supply circuit. The code is logged.
All sensors are set to default values.
262-4 5 Volt Sensor DC Power Supply : Voltage Below Normal The ECM has detected a voltage that is below normal in the 5 V supply circuit.
460-21 Fuel Pressure Sensor - After Fuel Filter : Data Drifted Low The ECM has determined that the supply voltage is not present at the fuel pressure sensor. The code is logged.
The sensor is set to the default value.
1785-21 Intake Manifold Pressure Sensor : Data Drifted Low The ECM has determined that the supply voltage is not present at the intake manifold pressure sensor. The code is logged.
The sensor is set to the default value.
2131-3 5 Volt Sensor DC Power Supply #2 : Voltage Above Normal The ECM has detected a voltage that is above normal in the 5 V supply circuit. The code is logged.
Engine power may be derated.
2131-4 5 Volt Sensor DC Power Supply #2 : Voltage Below Normal The ECM has detected a voltage that is below normal in the 5 V supply circuit.
3031-21 Intake Manifold #2 Pressure Sensor:Data Drifted Low The ECM has determined that the supply voltage is not present at the intake manifold pressure sensor. The code is logged.
The sensor is set to the default value. System OperationThe ECM supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Atmospheric pressure sensor
Buffer for the exhaust temperature sensors (left side)
Buffer for the exhaust temperature sensors (right side)
Engine oil pressure sensor
Fuel pressure sensor (filtered fuel pressure)
Intake manifold pressure sensors
Turbocharger compressor inlet pressure sensorsThe ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensor:
Coolant level sensors
Oil level sensors
Throttle position sensorThe supply voltage for the sensors is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal 2 of each sensor connector.The -21 code becomes active when the ECM determines that the 5 V supply is missing at the pressure sensor. The ECM sets the value of the suspect sensor to the default value.The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.Note: The throttle position sensor is not protected from overvoltage. A short from the supply line to the +Battery may damage the sensor. If any of the 8 V supply diagnostic codes are active, the throttle position sensor may be damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if the sensor has been damaged.
Illustration 1 g02272593
Schematic of the 5 V supply circuits
Illustration 2 g02274295
Schematic of the 8 V supply circuits
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 3 g02138858
Location of the ECM connectors (left side engine view)
(1) J1/P1 ECM connectors
(2) J2/P2 ECM connectors
Thoroughly inspect connectors (1) and (2). Inspect all of the connectors that are associated with the sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 4 g02138860
Terminal locations at the P1 ECM connector for the analog sensor supply and the digital sensor supply
(P1-2) Analog sensor supply
(P1-3) Analog sensor return
(P1-4) Digital sensor supply
(P1-5) Digital sensor return
Illustration 5 g02274476
Terminal locations at the P2 ECM connector for the analog sensor supplies
(P2-17) Return
(P2-30) Return
(P2-72) Analog sensor supply
(P2-81) Analog sensor supply
(P2-83) Return
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM. Expected Result:All connectors, pins, and sockets are coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Diagnostic Codes that are Active or Logged
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the ECM.
Monitor the active diagnostic code screen on Cat ET. Check and record any diagnostic codes that are active or logged. Look for the following diagnostic codes:
41-3
41-4
262-3
262-4
460-21
1785-21
2131-3
2131-4
3031-21Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Remove the electrical power from the ECM. Expected Result:No diagnostic codes are active or logged.Results: