855556 Mercury AIR SILENCER

Note: The following conditions must exist before any of the above codes will become active:
The ECM has been powered for at least 2 seconds.
There are no active 168-X diagnostic codes.The ECM will log the diagnostic code. If equipped, the warning light will come on.This procedure covers open circuit diagnostic codes and short circuit diagnostic codes that are associated with the following sensors that are connected to the ECM:
Coolant temperature sensor
Intake manifold air temperature sensor
Fuel temperature sensor
Air inlet temperature sensor
Exhaust Gas Recirculation (EGR) pre-cooler temperature sensor
EGR post-cooler temperature sensorThe following background information is related to this procedure:The temperature sensors have two terminals. The signal line is connected to each sensor connector terminal 1. Terminal 2 is the return line. The signal voltage from terminal 1 of each sensor is supplied to the appropriate terminal in the ECM.Pull-up VoltageThe ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage to detect an open in the signal circuit. When the ECM detects a voltage above a threshold on a signal circuit, an open circuit diagnostic code (XXX-3) is communicated to the engine ECM.If the sensor is disconnected, pull-up voltage at the connector indicates that the wires are not open or shorted to ground. If the sensor is disconnected, the absence of pull-up voltage indicates an open in the signal wire or a short to ground. If the sensor is disconnected and the voltage is different from pull-up voltage, the signal wire is shorted to another wire in the harness.
Illustration 1 g06498425
Schematic diagram for the engine temperature sensors
Note: All connectors may not be shown. Refer to the Electrical Schematic for the application for more information.Note: Refer to the Electrical Schematic for the application for the wiring information for the auxiliary pressure sensor and the transmission oil temperature sensor (if equipped).
Table 2
Troubleshooting Test Steps Values Results
1. Download Information Using the Electronic Service Tool
A. Use the electronic service tool to download the "Product Status Report" (PSR) with histograms before performing any troubleshooting or clearing any diagnostic codes.
Note: The downloaded information will be required by the Dealer Solutions Network (DSN) if troubleshooting assistance is required.
Downloaded information
Result: The information was successfully saved.
Proceed to Test Step 2.
Result: The electronic service tool information was not successfully saved.
Contact the Dealer Solutions Network (DSN) for guidance.
2. Create an Electronic Service Tool Snapshot (only applicable to 174–3 and 174–4 diagnostic codes)
A. Select "Snapshot Viewer" on the electronic service tool, using menus: Information -> Snapshot -> Viewer
B. Select the event code and then click "View Graph".
C. Select the following parameter and then click OK.
Engine Speed
D. Select Save to "File to save" a Snapshot File (*.xml). This file will contain all the data in the snapshot and not only the data shown on the graph.
Note: The downloaded information will be required by the DSN if troubleshooting assistance is required.
Snapshot saved
Result: The electronic service tool snapshot was successfully saved.
Proceed to Test Step 3.
Result: The electronic service tool snapshot was not successfully saved.
Contact the DSN for guidance.
3. Check for Diagnostic Tr