804178 Mercury SPRING

Table 1
Diagnostic Codes Table    
Code and Description     Conditions which Generate this Code     System Response    
41-3 8 Volt DC Supply voltage above normal     The digital sensor supply voltage is above normal for one second.
The Electronic Control Module (ECM) has been powered for 3 seconds.     The code is logged.
All sensors are set to default values.    
41-4 8 Volt DC Supply voltage below normal     The digital sensor supply voltage is below normal for one second.
The ECM has been powered for 3 seconds.    
100-10 Engine Oil Pressure Sensor abnormal rate of change     The signal voltage has not changed at a normal rate for 30 seconds.
Engine speed must be above 600 rpm.     The code is logged.
The value of the parameter is set to a gauge pressure of
600 kPa (87 psi).    
262-3 5 Volt Sensor DC Power Supply voltage above normal     The analog sensor supply voltage is above normal for one second.
The ECM has been powered for 3 seconds.     The code is logged.
All sensors are set to default values.    
262-4 5 Volt Sensor DC Power Supply voltage below normal     The analog sensor supply voltage is below normal for one second.
The ECM has been powered for 3 seconds.    
1785-10 Intake Manifold Pressure Sensor abnormal rate of change     The signal voltage has not changed at a normal rate for 30 seconds.
Engine speed must be above 1000 rpm.     The code is logged.
The value of the parameter will be set to
100 kPa (15 psi).    System OperationThe ECM supplies a regulated voltage of 5.0 The ECM supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Engine oil pressure sensor
Fuel pressure sensor
Intake manifold pressure sensor
Transmission oil pressure sensor
Transmission oil temperature sensorThe ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensors:
Coolant level sensor
Exhaust 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.If a -10 code is logged, this 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. If any of the 3 diagnostic codes are active, it is possible that a sensor has 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 g01373855
Schematic for the sensor supply circuit
Illustration 2 g03129076
Locations of the components for the sensor supply (typical left side engine view) (1) Coolant level sensor (2) Intake manifold pressure sensor (3) Engine oil pressure sensor (4) J2/P2 ECM connectors
Illustration 3 g03129556
(5) Fuel pressure sensor
Illustration 4 g01373963
Locations of the connectors for the analog sensors and the digital sensors (typical rear engine view) (6) Connector for the transmission pressure sensor (7) Connector for the exhaust temperature sensor (8) Connector for the transmission temperature sensor
Illustration 5 g01374012
Terminal locations at the P2 ECM connector for the sensor supply (P2-17) Analog return (P2-29) Digital sensor supply (P2-54) Analog return (P2-72) Analog sensor supply (P2-80) Analog sensor supply (P2-81) Digital sensor supply (P2-92) Digital return (P2-93) Digital return
Illustration 6 g01159881
Terminal locations at the sensor connector for the sensor supply (Terminal A) Sensor supply (Terminal B) Sensor return (Terminal C) Sensor signal
Table 2
Troubleshooting Test Steps     Expected Result     Result    
1. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM. Turn the keyswitch to the OFF position.
B. Thoroughly inspect the connectors for sensors (1 through 4). Also, thoroughly inspect connectors (5 through 8) .
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.
D. Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM.    
All 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.    
Result: The harness and connectors appear to be OK.
Proceed to Test Step 2.
Result: There is a problem with the connectors and/or wiring.
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 completely coupled.
Verify that the repair eliminates the