33048 Mercruiser SCREW, AIR HORN TO FLOAT BOWL (LONG)

Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
678-3
ECU 8 Volts DC Supply : Voltage Above Normal The digital sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
678-4
ECU 8 Volts DC Supply : Voltage Below Normal The digital sensor supply voltage is below normal for two seconds.
1180-3
Engine Turbocharger 1 Turbine Inlet Temperature : Voltage Above Normal The digital sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
1180-4
Engine Turbocharger 1 Turbine Inlet Temperature : Voltage Below Normal The digital sensor supply voltage is below normal for two seconds.
1181-3
Engine Turbocharger 2 Turbine Inlet Temperature : Voltage Above Normal The digital sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
1181-4
Engine Turbocharger 2 Turbine Inlet Temperature : Voltage Below Normal The digital sensor supply voltage is below normal for two seconds.
3509-3
Sensor Supply Voltage 1 : Voltage Above Normal The analog sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
3509-4
Sensor Supply Voltage 1 : Voltage Below Normal The analog sensor supply voltage is below normal for two seconds.
3510-3
Sensor Supply Voltage 2 : Voltage Above Normal The analog sensor supply voltage is above normal for two seconds. The code is logged.
All sensors are set to default values.
3510-4
Sensor Supply Voltage 2 : Voltage Below Normal The analog sensor supply voltage is below normal for two seconds.
108-21
Atmospheric Pressure Sensor : Data Drifted Low The 5 VDC supply to the sensor has been lost. The code is logged.
All sensors are set to default values.
3563-21
Engine Intake Manifold #1 Absolute Pressure : Data Drifted Low The 5 VDC supply to the sensor has been lost. The code is logged.
All sensors are set to default values.
5578-21
Engine Fuel Delivery Absolute Pressure : Data Drifted Low The 5 VDC supply to the sensor has been lost. The code is logged.
All sensors are set to default values.
5580-21
Engine Fuel Delivery Absolute Pressure : Data Drifted Low The 5 VDC supply to the sensor has been lost. The code is logged.
All sensors are set to default values. System Operation The Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Atmospheric pressure sensor
Crankcase pressure sensor
Filtered engine oil pressure sensor
Filtered fuel pressure sensor
Left turbocharger inlet pressure sensor
Right turbocharger inlet pressure sensor
Unfiltered engine oil pressure sensor
Unfiltered fuel pressure sensor
Turbocharger outlet 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 1 of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal 2 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.If applicable, when a -10 code is logged, this code indicates that the 5 V supply is not available at the sensor connector. During normal engine operation, each of the signals from the pressure sensors fluctuate slightly. When the 5 V supply becomes unavailable at the pressure sensor connector, the signal from that sensor floats to a midrange value. The signal will not fluctuate. If the signal from the sensor remains abnormally steady for more than 30 seconds, the ECM will activate this code.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has failed.
Illustration 1 g03321934
Schematic for the analog sensors
Illustration 2 g03322810
Schematic of the PWM sensors for the sensor signal circuit
Illustration 3 g03325947
P1 ECM connector
(P1-2) Analog sensor supply
(P1-3) Analog return
(P1-5) Digital return
(P1-18) Digital return
(P1-15) Left turbo inlet pressure
(P1-27) Right turbo inlet pressure
Illustration 4 g03325948
P2 ECM connector
(P2-15) Intake manifold pressure
(P2-16) Unfiltered fuel pressure
(P2-17) Analog return
(P2-27) Filtered fuel pressure
(P2-28) Filtered oil pressure
(P2-29) Digital supply
(P2-30) Analog return
(P2-33) Crankcase pressure
(P2-41) Gas pressure
(P2-54) Analog return
(P2-65) Right turbocharger turbine inlet temperature
(P2-66) Unfiltered oil pressure
(P2-72) Analog sensor supply
(P2-73) Left turbocharger turbine inlet temperature
(P2-78) Barometric pressure
(P2-80) Analog sensor supply
(P2-81) Analog sensor supply
(P2-82) Analog sensor supply
(P2-83) Analog return
(P2-93) Analog return
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 Troubleshoot