C7 and C9 Marine Engines Caterpillar

Use this procedure to troubleshoot any suspect problems with the following sensors:

• Primary engine speed/timing sensor

• Secondary engine speed/timing sensor

This procedure covers the following diagnostic codes:

• 190-11 Engine Speed Sensor mechanical failure

• 342-11 Secondary Engine Speed Sensor mechanical failure

The engine uses two engine speed/timing sensors. The primary engine speed/timing sensor and the secondary engine speed/timing sensor are used to detect the reference for engine speed and for engine timing from a unique pattern in the timing reference ring. The timing reference ring is located on the back of the camshaft gear. To determine rpm, the Electronic Control Module (ECM) counts the time between pulses that is created by the sensor as the gear rotates.

Under normal operation, the secondary engine speed/timing sensor is used to determine timing for starting purposes. The secondary engine speed/timing sensor is used to determine when the piston in the No. 1 cylinder is at the top of the compression stroke. When the timing has been established, the primary engine speed/timing sensor is then used to monitor engine speed.

When the timing has been established, the ECM triggers each injector in the correct firing order at the correct time. The actual timing and duration of each injection is based on engine rpm and on load.

If the engine is running and the signal from one sensor is lost, no change in engine performance will be noticed. If the engine is running and the signals from both sensors are lost, fuel injection will be terminated and the engine will be shut down by the ECM.

The engine will start when only one sensor signal is present. The engine will not start if the signals from both sensors are lost.

Both sensors are magnetic sensors. The two sensors are not interchangeable.

If a replacement of the ECM is required, the ECM parameters and the timing calibration can be transferred from the suspect ECM to the replacement ECM. This feature requires the Caterpillar Electronic Technician (ET) and this feature is only possible if the existing ECM can communicate with Cat ET. Use the "Copy Configuration - ECM Replacement" feature on Cat ET.

Note: Before replacing the ECM check the following components for possible damage:

• Speed/timing sensors

• Camshaft

• Cam gear

Complete all of the following tasks when you install a speed/timing sensor:

• Ensure that an O-ring is installed on the sensor. If the O-ring is damaged or missing, replace the O-ring.

• Lubricate the O-ring with oil.

• Ensure that the sensor is fully seated into the engine before tightening the bracket bolt.

• Ensure that the electrical connector is latched.

• Ensure that the harness is properly secured, and ensure that each tie-wrap is placed in the correct location.

Illustration 1	g01229299
Schematic for the engine speed/timing sensors

Test Step 1. Check for Diagnostic Codes

1. Connect Cat ET to the service tool connector. Refer to electronic troubleshooting Troubleshooting, "Electronic Service Tools".

2. Restore the electrical power to the ECM.

3. Start the engine and run the engine until the engine is at the normal operating temperature.

   Note: If the engine will not start, monitor the engine rpm on Cat ET while the engine is being cranked. Cat ET may need to be powered from another battery while the engine is being cranked.

4. Look for these codes on Cat ET:

   Note: Wait at least 30 seconds in order for any codes to become active.

   • 190-11

   • 342-11

Expected Result:

One or both of the diagnostic codes that are listed above are logged or active.

Note: If the engine will not start and Cat ET displayed 0 rpm during cranking, select "No Engine rpm".

Results:

• No Engine rpm - Engine rpm is not indicated on Cat ET. Proceed to Test Step 2.

• Active or logged code - There is an active diagnostic code or a logged diagnostic code for an engine speed/timing sensor. Proceed to Test Step 4.

• No codes - Neither code is active or logged.

  Repair: Refer to troubleshooting without a diagnostic code Troubleshooting.

  STOP

Test Step 2. Check the Installation of the Sensor Assembly

1. Remove the electrical power from the ECM.

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Illustration 2	g01180490
Left side view (1) Engine (2) Mounting flange (3) Bracket

2. Visually inspect the sensor assembly without removing the sensor assembly from the engine. Flanges (2) must be flush against engine (1) in order to ensure proper operation.

   Inspect bracket (3). Verify that the bracket securely holds the flanges of the sensors flush against the engine.

   Verify that the bracket is not bent. If the bracket is bent or if an obstruction is preventing the sensor assembly from being installed correctly, the engine will not start.

   Note: The bracket cannot be replaced separately.

3. Remove the sensor assembly from the engine. Inspect each sensor. Replace the sensor, if necessary.

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Illustration 3	g01180501
Exploded view of the engine speed/timing sensors (4) O-ring seals

4. Ensure that one O-ring (4) is installed on each sensor. Check the O-rings for damage. Replace the O-rings, if necessary.

Results:

• OK - The sensor assembly's components are OK.

  Repair: Perform the following procedure in order to properly install the sensor assembly:

  1. Lubricate each O-ring with engine oil.

  2. Fully seat the sensor assembly in the engine.

  3. Tighten the bracket bolt.

  4. Connect the sensor's electrical connectors. Verify that the connectors are latched on both sides.

  5. Ensure that the harness is properly secured, and that the tie-wraps are placed in the correct location.

  Proceed to Test Step 3.

• Not OK - At least one of the sensor assembly's components is not OK.

  Repair: Obtain a new sensor assembly. Perform the following procedure in order to properly install the sensor assembly:

  1. Lubricate each O-ring with engine oil.

  2. Fully seat the sensor assembly in the engine.

  3. Tighten the bracket bolt.

  4. Connect the sensor's electrical connectors. Verify that the connectors are latched on both sides.

  5. Ensure that the harness is properly secured, and that the tie-wraps are placed in the correct location.
  Verify that the problem is resolved.

  STOP

Test Step 3. Inspect the Electrical Connectors and the Wiring

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Illustration 4	g01181799
Typical left side engine view (5) connector for the primary engine speed/timing sensor (6) connector for the secondary engine speed/timing sensor (7) J2/P2 ECM connector

1. Thoroughly inspect connectors (5), (6), and (7). Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".

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Illustration 5	g01181800
Left side view (P2-46) Primary engine speed/timing sensor + (P2-47) Primary engine speed/timing sensor - (P2-35) Secondary engine speed/timing sensor + (P2-25) Secondary engine speed/timing sensor -

2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the engine speed/timing sensors.

3. Check the allen head screw on each ECM connector for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".

4. Check the harness and the wiring for abrasion and for pinch points from each sensor back to the ECM.

Expected Result:

All of the 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.

Results:

• OK - The harness and connectors appear to be OK. Proceed to Test Step 4.

• Not OK - The connectors and/or wiring are not OK.

  Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem.

  STOP

Test Step 4. Measure the Sensor Resistance through the Engine Harness

1. Disconnect the J2/P2 ECM connector.

2. If you are troubleshooting a problem with the primary engine speed/timing sensor, perform the following procedure:

   1. Measure the sensor's resistance between P2-46 (primary engine speed/timing +) and P2-47 (primary engine speed/timing -).

   2. Check for an intermittent open circuit or for a short circuit by moving the harness while you take the resistance measurement. Pull the wires that are directly behind the sensor or shake the wires that are directly behind the sensor.

      Resistance ... 75 to 230 Ohms

3. If you are troubleshooting a problem with the secondary engine speed/timing sensor, perform the following procedure:

   1. Measure the sensor's resistance between P2-35 (secondary engine speed/timing +) and P2-25 (secondary engine speed/timing -).

   2. Check for an intermittent open circuit or for a short circuit by moving the harness while you take the resistance measurement. Pull the wires that are directly behind the sensor or shake the wires that are directly behind the sensor.

      Resistance ... 600 to 1800 Ohms

Expected Result:

The resistance measurement is within the specifications.

Results:

• OK - The resistance measurement is within the specifications.

  Repair: Perform the following procedure:

  1. Temporarily install a new ECM. Refer to electronic troubleshooting Troubleshooting, "Replacing the ECM".

  2. Start the engine. Run the engine until the engine is at normal operating temperature.

  3. If the problem is resolved with the test ECM, connect the original ECM and verify that the problem recurs. If the problem returns with the original ECM, replace the ECM.

     Verify that the problem is resolved.

  4. If the problem is not resolved with the test ECM, connect the original ECM. There may be a problem with the camshaft and/or the cam gear. Refer to Disassembly and Assembly. There may also be a problem with the sensors. Check the sensors for damage.

     Verify that the problem is resolved.

  STOP

• Not OK - The readings are not within the specifications. The sensor resistance is not within the acceptable range when the sensor resistance is measured through the engine harness. Proceed to Test Step 5.

Test Step 5. Measure the Resistance of the Sensor

1. Disconnect the harness connector for the suspect sensor.

2. Thoroughly inspect the sensor's connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".

3. Measure the sensor's resistance between terminals A and B.

Expected Result:

For the primary engine speed/timing sensor, the resistance measurement is between 75 and 230 Ohms. For the secondary engine speed/timing sensor, the resistance measurement is between 600 and 1800 Ohms.

Results:

• OK - The reading is within the specification. There is a problem with the wiring between the engine speed/timing sensor and the ECM. There may be a problem with a connector.

  Repair: Repair the wiring and/or the connector. Replace parts, if necessary. Verify that the problem is resolved.

  STOP

• Not OK - The reading is not within the specification. There is an electrical problem with the engine speed/timing sensor.

  Repair: Perform the following procedure in order to check and install the new sensor assembly:

  1. Before you install the new sensor assembly, measure the resistance of the new sensors.

     If the resistance measurements of the new sensors are within the specifications, install the new sensor assembly in the engine according to the following procedure:

     1. Loosen the bolt and remove the bolt that holds the sensor to the engine.

     2. Ensure that an O-ring is installed on the new sensor assembly. Verify that the O-ring is free of damage.

     3. Seat the sensor and tighten the bolt.

     4. Ensure that the harness is secured in the proper location.

  2. Verify that the repair eliminates the problem.

  STOP