DTC Troubleshooting: U0073 (126-1)

DTC U0073: F-CAN Malfunction (Bus-Off)

1. Turn the ignition switch ON (II).

1. Clear the DTC with the HDS.

1. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0073 indicated?

YES | - | Go to Step 4 .
NO | - | Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the gauge control module, the VSA control unit (equip model only), and the ECM.■

1. Check for Body Electrical DTCs with the HDS.

Is DTC B1168, B1169 and/or B1178 indicated?

YES | - | Go to Step 5 .
NO | - | Do the gauge control module input test. ■

1. Turn the ignition switch OFF.

1. Remove the gauge control module.

1. Disconnect the gauge assembly 30P connector.

1. Disconnect the VSA control unit 47P connector (equip model only).

1. Disconnect ECM connector No. 2 (58P).

1. Check for continuity between ECM connector No. 2 terminals No. 47, No. 48 and body ground individually.

| *: | CANL line

Is there continuity?

YES | - | Repair short in the wire between the gauge control module, and the VSA control module, and ECM connector No. 2 terminal No. 47 (No. 48) * , go to Step 15 .
NO | - | Go to Step 11 .

1. Check for continuity between ECM connector No. 2 terminals No. 47 and No. 48.

Is there continuity?

YES | - | Repair short in the wire between ECM connector No. 2 terminals No. 47 (CANH line) and No. 48 (CANL line), then go to Step 15 .
NO | - | Go to Step 12 .

1. Check for continuity between ECM connector No. 2 terminal No. 47 and the following connector terminal.

   Connector | Terminal
   Gauge control module 30P | No. 24 (WHT)
   VSA control unit 47P | No. 14 (WHT)

Is there continuity between the ECM terminal and each of the terminals in the chart?

YES | - | Go to Step 13 .
NO | - | Repair open in the wire between the ECM and the appropriate connector, then go to Step 15 .

1. Check for continuity between ECM connector No. 2 terminal No. 48 and the following connector terminal.

   Connector | Terminal
   Gauge control module 30P | No. 23 (RED)
   VSA control unit 47P | No. 30 (RED)

Is there continuity between the ECM terminal and each of the terminals in the chart?

YES | - | Go to Step 14 .
NO | - | Repair open in the wire between the ECM and the appropriate connector, then go to Step 15 .

1. Refer to the following chart. Select the row that most closely represents the combination of DTCs retrieved from the ECM, VSA, and Body Electrical systems: Check connections at the control module indicated in the last column. If all the connections are OK, substitute another control module. After substituting the control module, go to step 15 and recheck.

   PGM-FI | VSA | Body Electrical | Control module
   U0155 | 86-1 | B1168 B1169 B1178 | Gauge Control module
   U0073 U0122 U0155 | 68-1 86-1 | B1168 B1169 B1178 | ECM
   U0073 U0122 U0155 | 68-1 86-1 | B1168 B1178 | VSA control unit

Are the DTCs still indicated?

YES | - | Substitute the remaining control module, one at time, unit the DTCs are no longer present, then replace the control module that made the DTCs go away. After replacing the faulty control module, go to Step 15 .
NO | - | Replace the faulty control module, then go to Step 15 .

1. Reconnect all connectors.

1. Turn the ignition switch ON (II).

1. Reset the ECM with the HDS.

1. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES | - | If DTC U0073 is indicated, check for poor connections or loose terminals at the gauge assembly, the VSA control unit, and the ECM, then go to Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | Troubleshooting is complete.■