804252 Mercury SPRING

Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
262-3 5 Volt Sensor DC Power Supply short to +batt The analog sensor supply voltage is above normal for 2 seconds. The code is logged.
All sensors are set to default values.
262-4 5 Volt Sensor DC Power Supply short to ground The analog sensor supply voltage is below normal for 2 seconds.
263-3 Digital Sensor Supply short to +batt The digital sensor supply voltage is above normal for 2 seconds.
263-4 Digital Sensor Supply short to ground The digital sensor supply voltage is below normal for 2 seconds. System OperationThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Aftercooler temperature sensor
Atmospheric pressure sensor
Coolant temperature sensor
Crankcase pressure sensor
Filtered engine oil pressure sensor
Filtered fuel pressure sensor
Turbocharger outlet pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Unfiltered engine oil pressure sensor
Unfiltered fuel pressure sensorThe ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensors:
Left turbocharger turbine inlet temperature sensor
Right turbocharger turbine inlet temperature sensorThe supply voltage for the sensors is routed from the ECM to terminal A of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal B of each sensor connector. 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 sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If the diagnostic code 262-3 or the diagnostic code 263-3 is logged, all of the sensors could have been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has failed.
Illustration 1 g03317117
Typical schematic for the +5V supply sensors
Illustration 2 g03318025
Typical schematic for the +8V supply sensors
Illustration 3 g03323203
Terminal locations at the P1 ECM connector
(P1-2) Analog supply
(P1-3) Analog return
(P1-4) Digital Supply
(P1-5) Digital Return
(P1-11) Left-hand turbo inlet exhaust temperature
(P1-12) Right-hand turbo inlet exhaust temperature
(P1-16) Filtered oil pressure
(P1-17) Unfiltered oil pressure
(P1-24) Filtered fuel pressure
(P1-25) Unfiltered fuel pressure
(P1-35) Analog return
(P1-39) Analog supply
Illustration 4 g03323204
Terminal locations at the P2 ECM connector.
(P2-36) Turbo outlet pressure
(P2-37) Atmospheric pressure
(P2-38) Left turbo inlet pressure
(P2-39) Right turbo inlet pressure
(P2-46) Crankcase pressure
(P2-54) Digital return
(P2-56) Digital supply
Illustration 5 g01240891
Sensor connector
(Terminal 1) Sensor supply
(Terminal 2) Sensor return
(Terminal 3) Signal
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect connectors (1) through (7). Inspect all of the connectors that are associated with the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
D. Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
E. Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.
Connectors
Results: The harness and connectors appear to be OK.
Proceed to Test Step 2
Results: 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.
2. Check for Diagnostic Codes that are Active or Logged
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector.
B. Restore the electrical power to the ECM.
C. 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:
- 678-3
- 678-4
- 3509-3
- 3509-4
- 3510-3
- 3510-4
Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
D. Turn the main disconnect switch to the OFF position.
Codes
Results: No diagnostic codes are active or logged.
Repair: There does not appear to be an electrical problem with the sensor supply at this time. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".
Results: Either the 678-3 or 678-4 diagnostic code is active or logged at this time.
There is an electrical problem with the digital sensor supply.
Proceed to Test Step 6
Results: Either the 3509-3, 3509-4, 3510-3, or 3510-4 diagnostic code is active or logged at this time.
There is an electrical problem with the analog sensor supply.
Proceed to Test Step 3
3. Check the Supply Voltage at the Sensor Connector
A. Disconnect the harness connectors for the following sensors:
- Crankcase pressure sensor
- Jacket water pressure sensor
- Filtered oil pressure sensor
- Unfiltered oil pressure sensor
- Filtered fuel pressure sensor
- Unfiltered fuel pressure sensor
- RH turbo inlet pressure sensor
- LH turbo inlet pressure sensor
- Atmospheric pressure sensor
- Intake manifold pressure sensor
B. Restore the electrical power to the appropriate ECM.