Troubleshooting for Marine Engine Electronic Displays Caterpillar

Test Step 1. Inspect the Electrical Connectors and the Wiring

1. Turn the keyswitch to the OFF position.

2. Check the connectors for the Electronic Control Module (ECM), the customer connectors, and the engine wiring for damage or incorrect attachment.

3. Check for the correct installation of the wires for the Cat Data Link. Refer to Installation Guide, "Wiring (Cat Data Link (CDL))" for additional information.

4. Check the electrical wiring and connectors of the following components for abrasion, for corrosion, or for incorrect attachment.

   • Global Positioning System Interface Module (GPSIM)

   • Engine Vision Interface Module (EVIM)

   • Engine Vision Display

   • Engine Monitoring System (EMS)

   • Computerized Monitoring System (CMS)

   • Harnesses and wiring

5. Verify that each individual ECM is programmed to the proper engine location.

6. Verify that the negative battery connections are secure and free from corrosion.

Expected Result:

All connectors, pins and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, of abrasion, and of pinch points.

Results:

• OK - The harnesses and wiring appear to be OK. Proceed to Test Step 2.

• Not OK - A problem has been found with a harness and/or wiring.

  Repair: Perform the following repair:

  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 problem.

  STOP

Test Step 2. Check the Display for Messages

A problem with the Cat Data Link will cause the following problems:

The main EMS display module or the CMS display shows an "ERROR" message intermittently after powerup.

OR

The tachometer for the EMS intermittently displays an "EE" message.

Note: The tachometer for the EMS may operate properly at times.

OR

The Engine Vision Display shows an "ERROR" message under all gauges.

Note: The Engine Vision Display may operate properly at times.

OR

The maintenance and/or the diagnostic screen for Engine Vision Display are not working properly and the message "WAITING FOR ECM" is displayed.

Expected Result:

The display modules do not show symptoms that are described in the above descriptions.

Results:

• OK - The display modules are not reporting communication errors with the Cat Data Link. The problem may be with the display module. Refer to the troubleshooting procedure for the suspect display.

• Not OK - One or more of the display modules are reporting a problem with the Cat Data Link. The problem is most likely in the vessel's wiring. Proceed to Test Step 4.

Test Step 3. Check the Supply Voltage at the Suspect Display

1. Turn the keyswitch to the ON position.
   Show/hide table

   Table 2

   	EMS	CMS	GPS	EVIM
   +Battery	Terminal 1	Terminal 1	B+	B+
   -Battery	Terminal 2	Terminal 2	B-	B-

2. Use signal reading probes to verify that the display modules are receiving the correct voltage. The display modules should be receiving 21 VDC to 27 VDC. The measured voltage of the Engine Vision Display should be between 9 VDC and 38 VDC.

3. Verify proper installation of the wires for the Cat Data Link on each ECM.
   Show/hide table

   Table 3

   	EMS	CMS	GPS	EVIM
   Cat Data Link +	Terminal 5	Terminal 23	D+	D+
   Cat Data Link −	Terminal 14	Terminal 24	D-	D-

Expected Result:

The wires for the Cat Data Link are installed properly.

Results:

• OK - The module is wired correctly. Proceed to Test Step 4.

• Not OK - The module is not wired correctly.

  Repair: Correct the wiring to the module.

  Verify that the repairs eliminated the problem.

  STOP

Test Step 4. Check the Cat Data Link for a Short in the Harness

1. Turn the keyswitch to the OFF position.

2. Isolate the circuit for the Cat Data Link.

   1. Disconnect the vessel's connectors from the ECM for each of the engines that are on the Cat Data Link.

   2. Disconnect the connections for the Cat Data Link from the EMS display module, the CMS, the EVIM, and the GPSIM.

   3. Disconnect all of the other modules that communicate on the Cat Data Link.

      Note: Failure to isolate the network completely will result in resistance measurements that are inaccurate.

3. Measure the resistance between the terminals for the CAT Data Link at the ECM connector for the following terminals:

   • Cat Data Link + to −Battery

   • Cat Data Link − to −Battery

   • Cat Data Link shield to −Battery

   • Cat Data Link + to +Battery

   • Cat Data Link − to +Battery

   • Cat Data Link shield to +Battery

   • Cat Data Link + to sensor common

   • Cat Data Link − to sensor common

   • Cat Data Link shield to sensor common

   Note: Wiggle the harness during the measurement in order to reveal an intermittent short.

Expected Result:

The correct resistance for all measurements is an open circuit.

Results:

• OK - All resistance measurements indicated an open circuit. Leave the connectors for each engine ECM and each module disconnected. Proceed to Test Step 5.

• Not OK - A short circuit was indicated by at least one of the resistance measurements.

  Repair: There is a short circuit in the harness. Repair the harness or replace the harness. Verify that the repair eliminates the original problem.

  STOP

Test Step 5. Check the Resistance of the Wiring for the Cat Data Link

1. Ensure that the network for the Cat Data Link is isolated from all external resistances.

   Note: Failure to isolate the network completely will result in resistance measurements that are inaccurate.

2. Fabricate a jumper wire that can be used to short circuit the Cat Data Link at one of the connectors for the engine ECM.

3. Use the jumper wire to short circuit the terminals for the Cat Data Link at the engine ECM.

4. Measure the resistance at all of the connectors for the Cat Data Link. Ensure that you include each segment of the wiring for the Cat Data Link.

   Note: Wiggle the harness during the measurements in order to reveal an intermittent open condition.

Expected Result:

The correct resistance for all measurements is a short circuit.

Note: A small resistance may be present in the wiring that can be attributed to length of the harness.

Results:

• OK - All resistance measurements indicated a short circuit. There are no open circuits in the harness. Restore the harness wiring to the original configuration. Proceed to Test Step 6.

• Not OK - An open circuit was indicated by at least one of the resistance measurements.

  Repair: There is an open circuit in the harness. Repair the harness or replace the harness. Verify that the repair eliminates the original problem.

  STOP

Test Step 6. Temporarily Bypass the Wiring for the Cat Data Link

Illustration 1	g00795800
Bypass harness for the EMS

Illustration 2	g00795875
Bypass harness for the EVIM

1. Turn the keyswitch to the OFF position.

2. Fabricate the appropriate bypass harness. Refer to Illustration 1, Illustration 2, Table 4, and Table 5 for the specifications of the bypass.

   Note: The length of the bypass harness should not exceed 1 m (3 ft).

3. Connect the bypass harness directly to the service tool connector that is on the engine harness. Connect the suspect display to the bypass harness.

4. Turn the keyswitch to the ON position. Check the operation of the suspect display.

Expected Result:

The display module works properly when the bypass harness is installed.

Results:

• OK - The suspect display operates correctly. The ECM and the display are OK. The problem is probably caused by the wiring for the Cat Data Link. Retest the network. Give additional attention to the condition of each connector and terminal strip.

• Not OK - The suspect display does not operate correctly.

  Repair: Connect the display to another engine. If the problem returns on the other engine, replace the display.

  If the display operates correctly, replace the ECM. Refer to Troubleshooting, "Replacing the ECM" that is for your particular engine.

  STOP