3406E, C-10, C-12, C-15, C-16 and C-18 On-highway Engines Caterpillar

Use this procedure under the following situation:

Use this procedure if the Caterpillar Electronic Technician (ET) will not power up or Cat ET will not communicate with the Electronic Control Module (ECM) through the cab data link connector.

The following background information is related to this procedure:

The ATA data link (American Trucking Association) is the standard data link that is used by the ECM to communicate with electronic service tools. The SAE specification J1587 defines the format of the messages and data that is communicated. The SAE specification J1708 defines the hardware requirements and the protocol of the serial communications. The Cat ET is an example of one of the electronic service tools. Some electronic dashboards use this data link to receive information. Some automatic transmissions also receive information from this data link.

The ECM provides the following two ATA data link connection terminals from the ECM vehicle harness connector J1:

• J1:8 (J1587 Data Link Positive)

• J1:9 (J1587 Data Link Negative)

The vehicle OEM provides twisted pair wiring from the ECM to the cab data link connector.

There are potentially several devices that are installed in the vehicle and these devices are connected to the ATA data link at one time. These devices include dash displays, trip recorders and transmission controls. These devices may cause problems with the data link. These problems can disrupt communications with the engine ECM.

Illustration 1	g00650338
Schematic for ATA data link with 6-pin connector

Illustration 2	g01156829
Schematic for ATA data link with 9-pin connector

Note: There are two possible configurations for the 9-pin connector.

The black 9-pin connector that is shown on this schematic connects directly to 157-4829 Cable Adapter. The diagnostic connector not shown is gray, has +Battery on pin A and −Battery on pin B and connects to service tool cable 139-4166 Data Link Cable As (ATA or Cat).

Test Step 1. Inspect Electrical Connectors and Wiring

Illustration 3	g01157130
Terminal locations for ECM

1. Thoroughly inspect the following electrical connectors:
   • ECM vehicle harness connector J1/P1

   • Cab data link connector

   • Firewall bulkhead connector

   • Electronic service tool connectors

   • ATA data link (terminal 8 and terminal 9) in the connectors

   Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

2. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the ATA data link.

3. Check the allen head screws on the ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

4. Check the harness and wiring for abrasion and for pinch points from the connector to the ECM.

   Refer to Illustration 3.

Expected Result:

All 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 wiring and the connectors are OK. Proceed to Test Step 2.

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

  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. Determine the Type of Problem with the Data Link

1. Connect Cat ET to the cab data link connector.

2. Start the engine.

Expected Result:

Result 1 The engine starts. The electronic service tool powers up and Cat ET communicates without error.

Result 2 The engine starts. Cat ET powers up but an error is displayed.

Result 3 The engine cranks but the engine will not start regardless of the condition of Cat ET.

Result 4 The engine will not crank regardless of the condition of Cat ET.

Result 5 The engine starts but Cat ET does not power up.

Note: Check the display screen or check the communication adapter display in order to determine if Cat ET has powered up. Cat ET will display information that shows if the tool is getting power. If Cat ET or the communication adapter powers up, the cab data link connector is receiving power.

Results:

• Result 1 - There is not a problem with the ATA data link at this time. If an intermittent condition exists, thoroughly inspect all wiring and connectors.

  Repair: Perform the following diagnostic procedure:Troubleshooting, "Electrical Connectors - Inspect"

  STOP

• Result 2 - Cat ET displays an error message. The ECM is receiving battery power. Proceed to Test Step 5.

• Result 3 - The engine will not start.

  Repair: Perform the following diagnostic procedure:Troubleshooting, "Engine Cranks But Will Not Start"

  STOP

• Result 4 - The engine will not crank.

  Repair: Perform the following diagnostic procedure:Troubleshooting, "Engine Will Not Crank"

  STOP

• Result 5 - Cat ET does not power up or the communications adapter does not power up. Ensure that the ECM is receiving the correct battery power. Proceed to Test Step 3.

Test Step 3. Check the Battery Voltage Supply to the Cab Data Link Connector

Illustration 4	g00650354
ATA Data Link connector

1. Turn the ignition key switch to the ON position.

2. Use a multimeter in order to measure the voltage from the +Battery terminal of the cab data link connector to the −Battery terminal of the cab data link connector.

   Refer to Illustration 4.

Expected Result:

The voltage is between 11.0 and 13.5 VDC for a 12 Volt system or between 22.0 and 27.0 VDC for a 24 Volt system.

Results:

• OK - The cab data link connector is currently receiving the correct voltage. Proceed to Test Step 4.

• Not OK - The cab data link connector is not receiving the correct voltage.

  Repair: Inspect the wiring and fuses to the connector. Repair the wiring or batteries and/or replace the wiring or batteries, as required. Send the vehicle to the OEM dealer for repair, if necessary. Verify that the repair eliminates the problem.

  STOP

Test Step 4. Change Electronic Service Tool Components

1. If another vehicle or another ECM is available, connect Cat ET to the other vehicle by using the same cables.

2. Turn the ignition key switch to the ON position. Determine if Cat ET operates correctly on the other ECM.

Expected Result:

Result 1 The original Cat ET works on another ECM.

Result 2 Cat ET does not work on the other ECM.

Results:

• Result 1 - The original Cat ET works on another ECM. Proceed to Test Step 5.

• Result 2 - Cat ET does not work on the other ECM.

  Repair: Obtain new cables for Cat ET.Verify that the problem is resolved.

  STOP

Test Step 5. Check the Battery Voltage at the ECM

Illustration 5	g00650356
ECM Breakout T-connector and terminal locations for ECM P1

1. Ensure that Cat ET is connected to the cab data link connector.

2. Disconnect vehicle harness connector P1 from ECM connector J1 and insert a 70-Terminal breakout T.

3. Turn the ignition key switch to the ON position.

4. Measure the voltage between P1:52 (Unswitched +Battery) and P1:65 (−Battery).

5. Measure the voltage between P1:70 (Ignition Key Switch) and P1:65 (−Battery).

   Refer to Illustration 5.

Expected Result:

The voltage is between 11.0 and 13.5 VDC for a 12 Volt system or between 22.0 and 27.0 VDC for a 24 Volt system.

Results:

• OK - The ECM is currently receiving the correct voltage. Proceed to Test Step 6.

• Not OK - The ECM is not receiving the correct voltage. Ensure that there is not an aftermarket engine protection switch that is overriding battery power to the ECM.

  Repair: Perform the following diagnostic procedure:Troubleshooting, "Ignition Key Switch Circuit and Battery Supply Circuit - Test"

  STOP

Test Step 6. Connect Cat ET Directly to the ECM

Show/hide table

Batteries give off flammable fumes which can explode. To avoid injury or death, do not strike a match, cause a spark, or smoke in the vicinity of a battery.

1. Turn the ignition key switch to the ON position.

2. Disconnect vehicle harness connector J1/P1 from the ECM.

3. Connect the 70-Pin connector of the 167-9225 Harness (Service Tool Adapter) to the ECM J1 connector. Connect the harnesses 9-pin connector to the Cat ET service tool adapter. Connect the red cable clamp to the +Battery. Connect the black cable clamp to the −Battery terminal.

Expected Result:

Cat ET is operating correctly.

Results:

• OK - Cat ET is operating correctly.

  Repair: Perform the following repair:There is a problem in the vehicle wiring, or another device in the vehicle is causing problems on the data link. Determine the device that is causing the problem or send the vehicle to the OEM dealer for repair.Verify that the repair eliminates the problem.

  STOP

• Not OK - Cat ET is not operating correctly. Verify that the 20 Amp fuse in the bypass harness is not open. A fuse that is open is a blown fuse. Proceed to Test Step 7.

Test Step 7. Connect Cat ET and the ECM to Another Battery

Show/hide table

Batteries give off flammable fumes which can explode. To avoid injury or death, do not strike a match, cause a spark, or smoke in the vicinity of a battery.

1. Connect the battery wires from the bypass harness to a different battery that is not on the vehicle.

Expected Result:

Cat ET is operating correctly.

Results:

• OK - Cat ET is operating correctly. The vehicle battery is causing the problem.

  Repair: Perform the following diagnostic procedure:Troubleshooting, "Ignition Key Switch Circuit and Battery Supply Circuit - Test"

  STOP

• Not OK - Cat ET not is operating correctly.

  Repair: Perform the following repair:

  1. Temporarily connect a test ECM.

  2. Remove all jumpers and replace all connectors.

  3. Recheck the system for active diagnostic codes.

  4. Repeat the Test Step.

  5. If the problem is resolved with the test ECM, reconnect the suspect ECM.

  6. If the problem returns with the suspect ECM, replace the ECM.

  7. Verify that the repair eliminates the problem.

  STOP