G3500 A3 Engines Caterpillar

Use this procedure to troubleshoot the following diagnostic codes:

• 1489-19 Left Turbo Turbine Outlet Temperature Sensor Received Network data in error

• 1490-19 Right Turbo Turbine Outlet Temperature Sensor Received Network data in error

• 1491-19 Right Turbo Turbine Inlet Temperature Sensor Received Network data in error

• 1492-19 Left Turbo Turbine Inlet Temperature Sensor Received Network data in error

• 2857-9 Exhaust Temperature Module abnormal update rate

• 1531-19 Engine Cylinder #1 Exhaust Port Temperature Sensor Received Network data in error through 1546-19 Engine Cylinder #16 Exhaust Port Temperature Sensor Received Network data in error

The Exhaust Temperature Module (ETM) is an electronic scanner for exhaust temperatures. The module monitors the following thermocouples:

• Thermocouples for each cylinder's exhaust port

• Thermocouples at the inlet of each turbocharger

• Thermocouples at the outlet of each turbocharger

The module displays the temperatures. The exhaust temperature module also sends the temperatures via the CAN data link to the engine ECM and the optional remote control panel for display. The exhaust temperature module has two switches that can be wired to alarms or to relays. Refer to Systems Operation Testing and Adjusting, KENR5473, "Exhaust Temperature Module" for additional information.

If the ECM cannot communicate with the exhaust temperature module, the ECM activates a diagnostic code for the parameter. A diagnostic code is probably caused by a problem with an electrical connector or a harness. The next likely cause is a problem with the exhaust temperature module. The least likely cause is a problem with the ECM.

Terminating resistors must be connected to each end of the CAN data link. The terminating resistors improve the communication between the devices. If there is an intermittent diagnostic code for any of the devices that are connected to the CAN data link, be sure to check the terminating resistors. One of the terminating resistors is connected to a splice in the wiring harness near the J1/P1 ECM connector. The other terminating resistor is connected to a "T" inside the optional remote panel. If the engine is not equipped with a remote panel, the other terminating resistor will be connected at the far end of interconnect harness. Refer to the appropriate documentation for the site in order to determine the location of this resistor.

This troubleshooting procedure may generate additional diagnostic codes. Correct the cause of the original diagnostic code before continuing. You clear the diagnostic codes after the problem is resolved.

Illustration 1	g01436016
Schematic for the circuit of the exhaust temperature module

Test Step 1. Inspect the Electrical Connectors and the Wiring

1. Set the engine control to the OFF/RESET position.

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Illustration 2	g01436495
Locations of the components for the exhaust temperature module (typical example) (1) J1/P1 ECM connectors (2) exhaust temperature module (3) Interface box

Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".

2. Thoroughly inspect ECM connectors (1) , the connectors for the exhaust temperature module (2) , and the connections in interface box (3) .

   1. Check the torque of the allen head screw for the ECM connectors.
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   Illustration 3	g01391850
   Terminal locations at the P1 ECM connector for the exhaust temperature module (34) CAN data link - (42) Shield (50) CAN data link +

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   Illustration 4	g01436520
   Terminal locations at the interface box for the exhaust temperature module (7) Keyswitch (10) -Battery (F1) Main fuse (15 Amp)

   2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the exhaust temperature module.

   3. Check the wiring for abrasion and for pinch points from the exhaust temperature module to the ECM.

Expected Result:

All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.

Results:

• OK - The components are in good repair with proper connections. Proceed to Test Step 2.

• Not OK - The components are not in good repair and/or at least one connection is improper.

  Repair: Perform the necessary repairs and/or replace parts, if necessary. Ensure that all of the seals are properly installed. Ensure that the connectors are properly engaged. Verify that the repair has eliminated the original problem.

  STOP

Test Step 2. Check for Diagnostic Codes

1. Establish communication between the Caterpillar Electronic Technician (ET) and the ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.

2. Look for the following diagnostic codes:
   • 1489-19 Left Turbo Turbine Outlet Temperature Sensor Received Network data in error

   • 1490-19 Right Turbo Turbine Outlet Temperature Sensor Received Network data in error

   • 1491-19 Right Turbo Turbine Inlet Temperature Sensor Received Network data in error

   • 1492-19 Left Turbo Turbine Inlet Temperature Sensor Received Network data in error

   • 2857-9 Exhaust Temperature Module abnormal update rate

   • 1531-19 through 1546-19 Engine Cylinder #1 Exhaust Port Temperature Sensor Received Network data in error through Engine Cylinder #16 Exhaust Port Temperature Sensor Received Network data in error

Expected Result:

There is not an active diagnostic code for the exhaust temperature module at this time.

Results:

• OK - There is not an active diagnostic code for the exhaust temperature module.

  Repair: There does not seem to be an electrical problem with the exhaust temperature module. If one of the codes is logged, there may be an intermittent problem in the harness or in a connector. There may be a problem with one of the fuses in the circuit.Check that electrical power is available at the exhaust temperature module. If an intermittent problem with the harness or a connector is suspected, refer to Troubleshooting, "Inspecting Electrical Connectors" for information that is related to troubleshooting intermittent electrical problems.

  STOP

• Not OK - There is an active diagnostic code that relates to the CAN data link. The ECM has detected a problem with the communication between the ECM and the exhaust temperature module. Proceed to Test Step 3.

Test Step 3. Check for Electrical Power at the Exhaust Temperature Module

1. Refer to Illustration 1 and Illustration 4. Measure the voltage for the exhaust temperature module at the engine interface box.

   The battery voltage must be between 18 V and 32 V in order for the exhaust temperature module to operate correctly. If a problem exists, correct the problem before you continue.

2. Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.

3. Disconnect the harness connector for the exhaust temperature module.

4. Restore electrical power to the ECM. Set the engine control to the STOP mode.

5. Measure the voltage between terminals 6 and 7 at the harness connector for the exhaust temperature module.

Results:

• OK - The voltage is within 2 V of the voltage at the engine power distribution box. Proceed to Test Step 4.

• Not OK - The voltage is not within 2 V of the voltage at the engine power distribution box.

  Repair: The exhaust temperature module is not receiving the proper operating voltage. There is a problem in the harness or in a connector. Determine the cause of the excessive voltage drop. Perform the necessary repairs. Verify that the repair eliminates the original problem.

  STOP

Test Step 4. Check the Resistance of the CAN Data Link at the Harness Connector for the Exhaust Temperature Module

Note: When the resistance measures between 114 Ohms and 126 Ohms, one of the resistors is not properly connected into the circuit.

1. Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.

2. Disconnect the harness connector for the exhaust temperature module.

3. Measure the resistance between terminals 8 and 9 on the harness connector for the exhaust temperature module.

Expected Result:

The resistance is between 57 Ohms and 63 Ohms.

Results:

• OK - The resistance is between 57 and 63 Ohms. Proceed to Test Step 5.

• Not OK - The resistance is not between 57 Ohms and 63 Ohms.

  Repair: Ensure that 2 termination resistors of the correct value are in place and properly connected to the circuit.

  Proceed to Test Step 5

Test Step 5. Check the Resistance of the CAN Data Link at the P1 ECM Connector

Note: Some devices will be spliced into the harness at different locations. Therefore also verify the correct resistance at the ECM. The ECM is the device the components are communicating with and the device that is presenting the code. Measure resistance at the ECM and check for continuity with the suspect device on the data link.

1. Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.

2. Disconnect the ECM J1/P1 connectors.

3. Measure the resistance between terminals P1-50 (CAN data link +) and P1-34 (CAN data link -).

Results:

• OK - The resistance is between 57 and 63 Ohms. Proceed to Test Step 6

• Not OK - The resistance is not between 57 Ohms and 63 Ohms.

  Repair: Ensure that 2 termination resistors of the correct value are in place and properly connected to P1-50 and P1-34.

  Proceed to Test Step 6

Test Step 6. Check the Continuity of the Wiring Harness for the CAN Data Link

1. Use a multimeter to check for continuity between the points that are listed in Table 1.
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   Table 1

   P1-34	ETM harness connector terminal 9
   P1-50	ETM harness connector terminal 8

Results:

• OK - There is continuity between the terminals of the connectors. Proceed to Test Step 7.

• Not OK - There is an open circuit between the terminals of the connectors.

  Repair: Perform the necessary repairs to the wiring and/or connectors. Replace parts, if necessary. Ensure that all of the seals are properly installed. Ensure that the connectors are properly engaged. Verify that the repair has eliminated the original problem.

  STOP

Test Step 7. Check the Harness for a Short Circuit

1. Measure the resistance between the points that are listed in Table 2. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
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   Table 2

   P1-34	All of the other terminals on the P1 connector
   	Ground strap for the ECM
   P1-50	All of the other terminals on the P1 connector
   	Ground strap for the ECM

Results:

• OK - Each check of the resistance indicates an open circuit. The harness is not shorted. Proceed to Test Step 8.

• Not OK - At least one check of the resistance indicates that there is continuity in the circuit.

  Repair: There is a short circuit in a harness. There may be a problem with a connector. Repair the wiring and/or the connector. Replace part, if necessary. Restore the wiring to the original configuration. Verify that the problem is resolved.

  STOP

Test Step 8. Determine if the ECM is the Problem

1. Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.

2. Temporarily install a new ECM.

3. Connect the exhaust temperature module.

4. Restore electrical power to the ECM. Set the engine control to the STOP mode.

5. Check for proper operation.

Results:

• OK - The new ECM resolved the problem.

  Repair: If the problem is resolved with the new ECM, install the original ECM and verify that the problem returns. If the new ECM operates correctly and the original ECM does not operate correctly, replace the original ECM. Refer to Troubleshooting, "ECM - Replace"

  STOP

• Not OK - The new ECM did not resolve the problem. Proceed to Test Step 9

Test Step 9. Determine if the Exhaust Temperature Module is the Problem

1. Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.

2. Temporarily install a new exhaust temperature module.

3. Restore electrical power to the ECM. Set the engine control to the STOP mode.

4. Check for proper operation.

Results:

• OK - The new exhaust temperature module resolved the problem.

  Repair: Permanently install the new exhaust temperature module.

  STOP

• Not OK - The problem is not resolved.

  Repair: Retest the system.

  STOP