898253T23 Mercruiser CAP, Distributor

Illustration 1 g01242577
Schematic for the 5 volt supplyTest Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g01199203
A typical left side view of the C7 engine (1) Fuel pressure sensor (2) Injection actuation pressure sensor (3) Atmospheric pressure sensor (4) Intake manifold (boost) pressure sensor (5) Engine oil pressure sensor (6) J2/P2 connectors (7) ECM (8) J1/P1 connectors
Thoroughly inspect connectors (6) and (7). Thoroughly inspect the connectors for each pressure sensor. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01223554
P2 terminals that are associated with the 5 volt supply for the pressure sensors (P2-17) Return (P2-54) Return (P2-72) +5 VDC (P2-80) +5 VDC
Illustration 4 g01123211
Connectors for the sensors (A) Supply (B) Return (C) Signal
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the pressure sensor supply.
Check the torque of the allen head screws for the ECM connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Check the harness and the wiring for abrasion and for pinch points from each sensor back to the ECM.Expected Result:All of the connectors, pins and sockets are completely 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 - The connectors and/or wiring are not OK.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem.STOPTest Step 2. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to electronic troubleshooting Troubleshooting, "Electronic Service Tools".
Restore the electrical power to the ECM.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active. Look for these codes:
262-03
262-04
100-10
1785-10Expected Result:One of the above codes is active.Results:
No active codes - None of the above codes are active.Repair: If any of the above codes are logged and the engine is not running properly, refer to Troubleshooting, "Troubleshooting Without a Diagnostic Code".If the engine is running properly at this time, there may be an intermittent problem in a harness that is causing the codes to be logged. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOP
Active -03 code - An -03 diagnostic code is active. Proceed to Test Step 3.
Active -04 code - An -04 diagnostic code is active. Proceed to Test Step 5.
Active -10 code - A -10 diagnostic code is active. Proceed to Test Step 4.Test Step 3. Check the Voltage on the +5 V Supply Wire
Remove the electrical power from the ECM.
Disconnect the harness connectors for the following sensors:
Injection actuation pressure sensor
Intake manifold (boost) pressure sensor
Atmospheric pressure sensor
Fuel pressure sensor
Engine oil pressure sensor
Restore the electrical power to the ECM.Note: Be sure to wiggle the harness during the following measurements in order to reveal an intermittent condition.
Measure the voltage between terminals A and B at each sensor connector on the engine harness.Expected Result:Each voltage measurement is 5.0 0.2 VDC.Results:
OK - Each voltage measurement is 5.0 0.2 VDC.Repair: Connect all of the sensor connectors. Clear all diagnostic codes. Check for active diagnostic codes. Wait at least 30 seconds so that any codes may become active. If the problem is intermittent, refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - At least one voltage measurement is not 5.0 0.2 VDC. There is a problem with the wiring or with the ECM. Proceed to Test Step 6.Test Step 4. Check the Voltage on the +5 V Supply Wire for the Suspect Sensor
Remove the electrical power from the ECM.
Disconnect the harness connectors for the suspect sensor.
Restore the electrical power to the ECM.Note: Be sure to wiggle the harness during the following measurement in order to reveal an intermittent condition.
Measure the voltage between terminals A and B on the harness connector for the suspect sensor.Expected Result:The voltage measurement is 5.0 0.2 VDC.Results:
Yes - The voltage measurement is 5.0 0.2 VDC. The 5 volt supply is present at the harness connector for the suspect sensor. However, there is an active -10 diagnostic code.Repair: Replace the suspect sensor.Verify that the problem is resolved.STOP
No - The voltage measurement is not 5.0 0.2 VDC. The 5 volt supply is not present at the harness connector. There is a problem with the wiring or with the ECM. Proceed to Test Step 6.Test Step 5. Disconnect the +5 V Pressure Sensors and Check for Active Diagnostic Codes
Disconnect the following sensors one at a time:
Injection actuation pressure sensor
Intake manifold (boost) pressure sensor
Atmospheric pressure sensor
Fuel pressure sensor
Engine oil pressure sensor
Wait for 30 seconds after you disconnect each sensor. Look for the active -04 diagnostic code to deactivate.Expected Result:The -04 diagnostic code deactivates when a particular sensor is disconnected.Results:
OK - The -04 diagnostic code deactivates when a particular sensor is disconnected.Repair: Connect the suspect sensor. If the code returns, replace the sensor.Connect all of the connectors. Verify that the problem is resolved.STOP
Not OK - The -04 diagnostic code remains after all of the sensors are disconnected. Leave the sensors disconnected. Proceed to Test Step 6.Test Step 6. Check the +5 V Supply Wire for a Short to Engine Ground or a Short Circuit
Remove the electrical power from the ECM.
Disconnect the P2 connectors.