DTC P0638:00

Throttle valve actuator control range/performance problem

DETECTION CONDITION

• The PCM compares the actual TP with the target TP. If the difference is more than the threshold value, the PCM determines that there is a throttle valve actuator control range/performance problem.

Diagnostic support note

• This is a continuous monitor (CCM).

• The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

• FREEZE FRAME DATA/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Restricts the upper limit of the engine speed.

• Stops the drive-by-wire control (throttle valve is open at approx. 8 ° by return spring force).

POSSIBLE CAUSE

• Throttle body connector or terminals malfunction

• Short to ground in wiring harness between the following terminals:

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

• PCM connector or terminals malfunction

• Short to power supply in wiring harness between the following terminals:

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

• Open circuit in wiring harness between the following terminals:

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

• Throttle valve actuator malfunction

• Throttle valve malfunction

• PCM malfunction

STEP

INSPECTION

ACTION

1

• Perform the Freeze Frame PID Data Access Procedure.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• Is the DTC P0638:00 on FREEZE FRAME DATA?

Yes

Go to the next step.

No

Go to the troubleshooting procedure for DTC on FREEZE FRAME DATA.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

2

NOTE:

• Recording can be facilitated using the screen capture function of the PC.

• Record the FREEZE FRAME DATA/snapshot data on the repair order.

—

Go to the next step.

3

• 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.

4

• Switch the ignition off.

• Disconnect the throttle body 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 10.

No

Go to the next step.

5

• Verify that the throttle body connector is disconnected.

• Inspect for continuity between the following terminals (wiring harness-side) and body ground:

• Throttle body terminal E

• Throttle body terminal F

• Is there continuity?

Yes

Disconnect the PCM connector and inspect the wiring harness for short to ground.

• 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 the following terminals:

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

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 2.0].)

Go to Step 10.

No

Go to the next step.

6

• 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 10.

No

Go to the next step.

7

• Verify that the throttle body and PCM connectors are disconnected.

• Switch the ignition ON (engine off).

  NOTE:

  • Another DTC may be stored by the PCM detecting an open circuit.

• Measure the voltage at the following terminals (wiring harness-side):

• Throttle body terminal E

• Throttle body terminal F

• 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 the following terminals:

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

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.

If there is no common connector:

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

Go to Step 10.

8

• Verify that the throttle body and PCM connectors are disconnected.

• Switch the ignition off.

• Inspect for continuity between the following terminals (wiring harness-side):

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

• 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 the following terminals:

• Throttle body terminal E—PCM terminal 1CG

• Throttle body terminal F—PCM terminal 1CC

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 10.

9

• Perform the Electronic Control Throttle Operation Inspection.

  (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the throttle body, then go to the next step.

(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

10

• Always reconnect all disconnected connectors.

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

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Perform the KOEO or KOER self test.

  (See KOEO/KOER SELF TEST [PCM (SKYACTIV-G 2.0)].)

• 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 2.0].)

Go to the next step.

No

Go to the next step.

11

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

No

DTC troubleshooting completed.