DTC U0284:00

LIN communication system: Communication error between active air shutter and PCM

DETECTION CONDITION

• PCM detects a communication error between the PCM and active air shutter.

Diagnostic support note

• This is a continuous monitor (other).

• The check engine light does not illuminate.

• FREEZE FRAME DATA (Mode 2) is available.

• Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Stops active air shutter control.

POSSIBLE CAUSE

• Communication line between active air shutter and PCM malfunction

• Active air shutter connector or terminals malfunction

• Short to ground or open circuit in active air shutter power supply circuit

• Short to ground in wiring harness between ENGINE3 15 A fuse and active air shutter terminal A

• ENGINE3 15 A fuse malfunction

• Open circuit in wiring harness between active air shutter terminal A and main relay terminal C

• Open circuit in wiring harness between active air shutter terminal D and body ground

• Short to ground in wiring harness between active air shutter terminal C and PCM terminal 2Z

• PCM connector or terminals malfunction

• Short to power supply in wiring harness between active air shutter terminal C and PCM terminal 2Z

• Open circuit in wiring harness between active air shutter terminal C and PCM terminal 2Z

• Active air shutter malfunction

• PCM malfunction

STEP

INSPECTION

ACTION

1

• Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Switch the ignition off.

• Disconnect the active air shutter connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 11.

No

Go to the next step.

4

• Verify that the active air shutter connector is disconnected.

• Switch the ignition ON (engine off).

• Measure the voltage at the active air shutter terminal A (wiring harness-side).

• Is the voltage B+?

Yes

Go to the next step.

No

Inspect the ENGINE3 15 A fuse.

• If the fuse is blown out:

• Refer to the wiring diagram and verify whether or not there is a common connector between ENGINE3 15 A fuse and active air shutter terminal A.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

• Replace the fuse.

• If the fuse is damaged:

• Replace the fuse.

• If the fuse is normal:

• Refer to the wiring diagram and verify whether or not there is a common connector between main relay terminal D and active air shutter terminal A.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 11.

5

• Verify that the active air shutter connector is disconnected.

• Switch the ignition off.

• Inspect for continuity between active air shutter terminal D (wiring harness-side) and body ground.

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between active air shutter terminal D and body ground.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Inspect for the following:

• Open circuit between active air shutter and body ground

• Loose or lifting ground point

• Repair or replace the malfunctioning part.

Go to Step 11.

6

• Verify that the active air shutter connector is disconnected.

• Inspect for continuity between active air shutter terminal C (wiring harness-side) and body ground.

• Is there continuity?

Yes

If the short to ground circuit could be detected in the wiring harness:

• Refer to the wiring diagram and verify whether or not there is a common connector between active air shutter terminal C and PCM terminal 2Z.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

If the short to ground circuit could not be detected in the wiring harness:

• Replace the PCM (short to ground in the PCM internal circuit).

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to Step 11.

No

Go to the next step.

7

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 11.

No

Go to the next step.

8

• Verify that the active air shutter and PCM connectors are disconnected.

• Switch the ignition ON (engine off).

• Measure the voltage at the active air shutter terminal C (wiring harness-side).

• Is the voltage 0 V?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between active air shutter terminal C and PCM terminal 2Z.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

• Repair or replace the malfunctioning part.

• Repair or replace the wiring harness which has a short to power supply.

Go to Step 11.

9

• Verify that the active air shutter and PCM connectors are disconnected.

• Switch the ignition off.

• Inspect for continuity between active air shutter terminal C (wiring harness-side) and PCM terminal 2Z (wiring harness-side).

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between active air shutter terminal C and PCM terminal 2Z.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 11.

10

• Inspect the active air shutter.

  (See ACTIVE AIR SHUTTER INSPECTION.)

• Is there any malfunction?

Yes

Replace the active air shutter, then go to the next step.

(See ACTIVE AIR SHUTTER REMOVAL/INSTALLATION.)

No

Go to the next step.

11

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See CLEARING DTC [SKYACTIV-G 2.5].)

• Start the engine.

• Drive the vehicle at 10 km/h or more for approx. 1 min.

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to the next step.

No

Go to the next step.

12

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

DTC troubleshooting completed.