95395 1 Mercury CLAMP

Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
190-8 Engine Speed Sensor : Abnormal Frequency, Pulse Width, or Period The engine is running for more than 3 seconds.
The pattern from the timing ring for the crankshaft speed/timing sensor is lost for 2 seconds. The engine speed from this sensor is ignored.
The code is active.
The code is logged if the pattern from the timing ring returns for 5 seconds.
342-8 Secondary Engine Speed Sensor : Abnormal Frequency, Pulse Width, or Period The engine is running for more than 3 seconds.
The Electronic Control Module (ECM) detects an abnormal signal frequency for the right camshaft speed/timing sensor. The code is latched in the active state until the power to the ECM is cycled.
The offset for the timing calibration is set to zero while the diagnostic code is active.
The sensor is ignored. The engine speed is calculated by using only the signal from the primary speed/timing sensor.
342-11 Secondary Engine Speed Sensor : Other Failure Mode The engine is in run mode for more than 5 seconds.
The condition is checked once after each start-up cycle.
The position of the primary speed/timing sensor in relation to the position of the secondary speed/timing sensor may be out of specifications.
The polarity of the sensor wiring may be reversed. The code is latched in the active state until the power to the ECM is cycled.
The offset for timing calibration is set to zero while the diagnostic code is active.
2710-8 Engine Tertiary Speed Sensor : Abnormal Frequency, Pulse Width, or Period The engine is in run mode for more than 3 seconds.
The ECM detects an abnormal signal frequency for the left camshaft speed/timing sensor. The sensor is ignored. The engine speed is calculated by using only the signal from the primary speed/timing sensor.
2710-11 Engine Tertiary Speed Sensor : Other Failure Mode The engine is in run mode for more than 5 seconds.
The condition is checked once after each start-up cycle.
The position of the primary speed/timing sensor in relation to the position of the secondary speed/timing sensor may be out of specifications.
The polarity of the sensor wiring may be reversed. The code is latched in the active state until the power to the ECM is cycled. This engine is equipped with three engine speed/timing sensors. The primary speed/timing sensor is mounted inside the engine crankcase and toward the left rear section of the engine. This sensor utilizes the teeth of the crankshaft gear on the rear gear to sense the engine speed and the crankshaft position. The primary speed/timing sensor for the engine is the crankshaft speed/timing sensor.The secondary speed/timing sensor and the tertiary speed/timing sensor are located on the top rear portion of the engine. Both of these sensors utilize the teeth of the camshaft gear on the rear gear group to sense the engine speed and the camshaft position. A single tooth for both of these gears has been partially removed in order to provide a timing reference for the ECM.Under normal operation, the ECM utilizes the signal from the primary speed/timing sensor to determine the crankshaft position for an accurate fuel delivery and timing. This feature eliminates the need for a separate procedure for timing calibration. A timing offset is determined during each engine start-up. The value of the timing offset is stored in the non-volatile memory of the ECM until the successful completion of the next engine start-up. If a failure mode for the primary engine speed/timing sensor is detected during engine start-up, timing calibration is aborted. The value of the timing offset stored in ECM memory will be used. This value will continue to be used for the engine timing calibration until the diagnostic is resolved. A timing calibration cannot be performed manually on this engine.The fuel delivery to the engine is synchronized by the signal from the secondary speed/timing sensor (RH). If a failure mode for the primary speed/timing sensor is detected, the ECM will use the signal from this sensor for fuel delivery and timing.Note: The locations for the sensors are identified as if the sensors are viewed from the rear of the engine. Refer to Illustration 7.For this application, the tertiary speed/timing sensor (LH) is provided as a backup for the secondary speed/timing sensor (RH). The signal from the tertiary sensor will be used if a failure of the secondary speed/timing sensor (RH) is detected. The ECM will use the tertiary sensor to provide the functionality of the failed sensor.Use Caterpillar Electronic Technician (ET) in order to view the status of the engine speed sensors.The signal from any two engine speed/timing sensors is necessary for the engine to be started. The signal from any single speed/timing sensor is necessary for the engine to run. The speed/timing sensors are not interchangeable. Do not attempt to switch the positions of the sensors.Complete all of the following tasks when you are installing the speed/timing sensors:
Ensure that an O-ring is installed on each sensor.
If an O-ring is damaged or missing, replace the O-ring.
Lubricate the O-rings with oil prior to installation of the sensor.
Ensure that the sensor assembly is fully seated into the engine before tightening the bracket bolt.
Ensure that each electrical connector is securely latched.
Ensure that the harness is properly secured, and ensure that each tie-wrap is placed in the correct location.
Illustration 1 g02459060Schematic for the engine speed/timing circuit
Table 2
Troubleshooting Test Steps Values Results
1. Check for Diagnostic Codes
A. Remove electrical power from the ECM.
B. Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
C. Restore electrical power to the ECM.
D. Start the engine and run the engine until the engine is at normal operating temperature.
Note: If the engine will not start, monitor the "No Start Parameters" parameter category on Cat ET while the engine is being cranked. Check each of the engine speed parameters for engine speed. You may have to power Cat ET from another battery while the engine is being cranked.
E. Look for these codes on Cat ET:
- 190-08
- 342-08
- 342-11
- 2710-08
- 2710-11
Note: These diagnostic codes