C27 and C32 Tier 4 Engines Caterpillar

This procedure covers the following codes:

The aftertreatment identification module sends a digital signal to the engine ECM in order to ensure that the correct CEM is installed to the engine.

If more than 25 hours (total operating hours) have been accumulated on the engine, the aftertreatment identification module will cease to send the signal. The diagnostic codes that are listed in Table 1 will be disabled.

Illustration 1	g02231895
Schematic for the aftertreatment identification module

Test Step 1. Check for Active Diagnostic Codes

1. Establish communication between the Caterpillar Electronic Technician (ET) and the ECM.

2. Download the "Product Summary Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.

Results:

• Active 5576-2 or 5577-2 - A 5576-2 or 5577-2 diagnostic code is active. Proceed to Test Step 4.

• Active 5576-8 or 5577-8 - A 5576-8 or 5577-8 diagnostic code is active. Proceed to Test Step 2.

• Active 5576-14 or 5577-14 - A 5576-14 or 5577-14 diagnostic code is active. Proceed to Test Step 4.

Test Step 2. Inspect the Electrical Connectors and the Wiring

Show/hide table

Illustration 2	g02133313
Location of the components for the aftertreatment identification module (1) CEM identification plate (2) Aftertreatment identification module

Show/hide table

Illustration 3	g02231881
Location of the connectors for the aftertreatment identification modules (3) Aftertreatment #2 identification module (4) Aftertreatment #1 identification module (5) J2/P2 ECM connector

1. Thoroughly inspect the connector for the aftertreatment identification modules (3) and (4). Also, thoroughly inspect the J2/P2 ECM connector (5). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
   Show/hide table

   Illustration 4	g02156576
   Terminal locations at the P2 ECM connector for the aftertreatment identification module (P2-65) Signal for the aftertreatment identification module #2 (P2-73) Signal for the aftertreatment identification module #1 (P2-82) Return (P2-92) Analog supply

   Show/hide table

   Illustration 5	g01994856
   Terminal locations at the connector for the aftertreatment identification module (Terminal 1) Analog supply (Terminal 3) Aftertreatment identification module (Terminal 6) Return

2. Perform a 45 N (10 lb) pull test on each of the wires in the connectors that are associated with the aftertreatment identification module.

3. Check the torque of the allen head screw on each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.

4. Check the harness for abrasion and pinch points from the aftertreatment identification module back to the ECM.

Expected Result:

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

Results:

• OK - All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. Proceed to Test Step 3.

• Not OK - There is a problem with the connectors and/or wiring.

  Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are coupled.

  Use Cat ET to clear all logged diagnostic codes and then verify that the repair has eliminated the fault.

  STOP

Test Step 3. Measure the Supply Voltage at the Connector for the Aftertreatment Identification Module

1. Turn the keyswitch to the OFF position.

2. Disconnect the aftertreatment identification module from the harness.

3. Turn the keyswitch to the ON position.

4. Measure the voltage at the plug for the aftertreatment identification module from the terminal for the analog supply to the terminal for the return.

Expected Result:

The supply voltage at the connector is 5.0 ± 0.2 VDC.

Results:

• OK - The supply voltage is correct. Proceed to Test Step 4.

• Not OK - The supply voltage at the connector is not 5.0 ± 0.2 VDC. There is a problem in the supply circuit for the aftertreatment identification module.

  Repair: Refer to Troubleshooting, "Sensor Supply - Test" for information that is related to troubleshooting the supply circuit.

  STOP

Test Step 4. Manually Enter the Aftertreatment Identification Information

Note: Factory Passwords are required for this procedure.

1. Confirm that a certified CEM is installed on the engine.

2. Record the "CEM Serial Number" and the "Configuration Group" from the CEM identification plate.

3. Contact your local Caterpillar dealer for a list of approved CEM configurations for your engine.

   Note: Contact your Technical Communicator (TC), if necessary.

4. Verify that the CEM is a certified match with the engine.

Expected Result:

The CEM is a certified match with the engine.

Results:

• OK - The CEM is a certified match with the engine.

  Repair: Perform the following procedure.

  1. Establish communication between Cat ET and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.

  2. Select the "Service" drop-down menu to navigate to the "Configuration" screen.

  3. Program the "Factory Installed Aftertreatment #1 Identification Number" with the serial number from the CEM identification plate.

  STOP

• The CEM is not a certified match to the engine. -

  Repair: Replace the CEM with a certified match to the engine. Refer to Disassembly and Assembly for removal and installation procedures. When the new CEM is installed, the aftertreatment identification module will begin communicating with the ECM and the diagnostic code will be cleared.

  The engine ECM will only communicate with the CEM if there are less than a total of 100 operating hours on the engine. If there are more than 100 operating hours on the engine, the CEM information must be programmed into the ECM by using Cat ET.

  STOP