825251 3 Mercury GASKET

Table 1
Diagnostic Codes Table
CDL Code and Description Comments
41-3
8 VDC Supply : Voltage Above Normal The code is logged.
41-4
8 VDC Supply : Voltage Below Normal The code is logged.
262-3
5 V Sensor DC Power Supply : Voltage Above Normal The code is logged.
All sensors are set to default values.
262-4
5 V Sensor DC Power Supply : Voltage Below Normal The code is logged.
All sensors are set to default values.
269-3
5 V Sensor DC Power Supply #2 : Voltage Above Normal The code is logged.
Engine power may be derated.
269-4
5 V Sensor DC Power Supply #2 : Voltage Below Normal The code is logged.
Engine power may be derated.
460-21
Fuel Pressure Sensor - After Fuel Filter : Data Drifted Low The code is logged.
The 5 VDC supply to the sensor has been lost.
1785-21
Intake Manifold Pressure Sensor : Abnormal Rate of Change The ECM detects supply voltage that is not in the acceptable range.
The code is logged. The value of the parameter is set to a gauge pressure.
2131-3
5 v Sensor DC Power Supply #2 : Voltage Above Normal The code is logged.
Engine power may be derated.
2131-4
5 v Sensor DC Power Supply #2 : Voltage Below Normal The code is logged.
Engine power may be derated.
3528-21
Barometric Pressure Sensor:Data Drifted Low The code is logged.
The 5 VDC supply to the sensor has been lost.
Illustration 1 g06114612
The signal wires are not shown.
Note: For "Sensor Supply # 2" refer to the application-specific wiring diagram for the J1 connector.Probable Causes
Codes
Sensors
Sensor supply voltageRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
B. Turn the keyswitch to ON.
C. Determine if a diagnostic trouble code is present.
Codes
Result: A -3 or -4 code is present.
Proceed to Test Step 2.
Result: A -21 code is present.
Proceed to Test Step 3.
2. Check for a Failed Sensor
A. Connect to Cat ET.
B. Turn the keyswitch to ON.
C. Disconnect a sensor on the suspect sensor supply circuit.
D. Monitor Cat ET while the sensor is disconnected to see if the active code changes to logged.
E. Connect the suspect sensor to the wiring harness
F. Repeat steps C through E for each sensor on the suspect sensor supply.
Sensor
Result: The suspect sensor supply active code changes to logged when a sensor is unplugged.
Repair: Replace the failed sensor.
Result: The suspect sensor supply active code remains active after all sensors on the sensor supply circuit have been checked.
Repair: A failed wiring harness has been detected. Repair or replace the wiring harness.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Sensor Supply Voltage
A. Turn the keyswitch to OFF.
B. Unplug the suspect sensor from the wiring harness.
C. Place a jumper wire between pin 1 and pin 2 on the suspect sensor wiring harness connector.
D. Connect to Cat ET.
E. Turn the keyswitch to ON.
F. Monitor the diagnostic codes using Cat ET.
Sensor supply voltage
Result: A -4 code is activated on the suspect sensor supply.
Repair: Remove the sensor. Check the sensor passage for a blockage or obstruction. Also, check for moisture frozen in the lines. If blockage is not found, replace the sensor.
Result: A -4 code is not activated on the suspect sensor supply.
Repair: The problem is in the wiring from the ECM to the sensor connector. Repair the wiring or replace the wiring.
If the problem is not resolved, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).