78266A 1 Mercruiser WIRING HARNESS (INBOARD)

Table 1
J1939 Code and Description CDL Code and Description Comment
1076-7
Engine Fuel Injection Pump Fuel Control Valve : Not Responding Properly 18-7
Fuel Control Valve : Not Responding Properly The commanded Fuel Control Valve (FCV) position does not match the actual FCV position.
1076-8
Engine Fuel Injection Pump Fuel Control Valve : Abnormal Frequency, Pulse Width, or Period 18-8
Fuel Control Valve : Abnormal Frequency, Pulse Width, or Period The PWM signal between the FCV and the ECM has been lost.
1076-12
Engine Fuel Injection Pump Fuel Control Valve : Failure 18-12
Fuel Control Valve : Failure A failed FCV has been detected.
3597-6
ECU Power Output Supply Voltage #1 : Current Above Normal 1028-6
Power Supply Control 1 : Current Above Normal A failed power supply to the fuel control valve has been detected.
Illustration 1 g06362136Recommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Determine if a code is active or logged.
Codes
Result: An 18-7, 18-11, 18-12, 1076-7, 1076-11, or 1076-12 code is present.
Repair: A failed FCV has been detected.
1. Release the pressure in the high-pressure rail by loosening the end plug on one of the last two fuel accumulators. Refer to Testing and Adjusting, "Fuel Rail Pressure - Release" for instructions on how to release the pressurized fuel.
2. Verify the "Fuel Rail Pressure" reading in ET is 0 8 MPa (0 1160 psi) prior to servicing the fuel system.
3. Replace the FCV.
Proceed to Test Step 9.
Result: An 18-8 or 1076-8 code is present.
Proceed to Test Step 2.
Result: A 1028-6 or 3597-6 code is active.
Proceed to Test Step 5.
2. Check the Wiring Between the ECM and the FCV for an Open Circuit
A. Turn the keyswitch to OFF.
B. Disconnect the fuel control valve from the wiring harness.
C. Disconnect the ER-C2 ECM connector from the engine ECM.
D. Measure the resistance between pin-48 on the ER-C2 ECM connector and pin-11 on the FCV connector.
Open Circuit
Results: Less than 10 ohms of resistance between pin-48 on the ER-C2 engine ECM connector and pin-11 on the FCV connector.
Proceed to Test Step 3.
Results: More than 10 ohms of resistance between pin-48 on the ER-C2 engine ECM connector and pin-11 on the FCV connector.
Repair: An open circuit in the wiring harness has been detected. Repair or replace the wiring harness as necessary.
Proceed to Test Step 9.
3. Check the Wiring Between the ECM and the FCV for a Short Circuit to Ground
A. Turn the keyswitch to OFF.
B. Disconnect the fuel control valve from the wiring harness.
C. Disconnect the ER-C2 ECM connector from the engine ECM.
D. Measure the resistance between pin-11 on the FCV connector and a known good ground.-
Short Circuit
Results: There were more than 100 K ohms of resistance between pin-11 on the FCV connector and a known good ground.
Proceed to Test Step 4.
Results: There were less than 100 K ohms of resistance between pin-11 on the FCV connector and a known good ground.
Repair: A short circuit to ground in the wiring harness has been detected. Repair or replace the wiring harness as necessary.
Proceed to Test Step 9.
4. Check the Wiring Between the ECM and the Fuel Control Valve (FCV) for a Pin to Pin Short Circuit
A. Turn the keyswitch to OFF.
B. Disconnect the fuel control valve from the wiring harness.
C. Disconnect the ER-C2 ECM connector from the engine ECM.
D. Measure the resistance between pin-48 on the ER-C2 ECM connector and