DTC P0488 2AD-FHV

The ECM opens and closes the throttle valve using a rotary solenoid type actuator. Due to opening and closing the valve, the exhaust gas recirculation volume can be properly controlled. Also, engine vibration and noise will be reduced by closing the valve when the engine is stopped.
Toyota fault code list DTC P0488

DTC No.	DTC Detection Condition	Trouble Area
P0488	When either condition below is met: When throttle valve remains closed despite ECM's signal to open valve (1 trip detection logic) When throttle valve remains open despite ECM's signal to close valve (1 trip detection logic)	Throttle valve stuck Throttle valve does not move smoothly Open or short in throttle valve circuit Open or short in throttle valve position sensor circuit Throttle position sensor (built in diesel throttle body assembly) ECM

HINT:

After confirming DTC P0488, check the throttle position.

Reference:

Condition	Throttle Valve Position
Moment when accelerator pedal is further depressed or released at 3,000 rpm	Opening angle varies smoothly

The ECM opens and closes the throttle valve by adjusting the current flowing to the rotary solenoid with a duty ratio. If the throttle valve does not move smoothly or is stuck, the duty ratio used during valve movement control increases or decreases greatly, and the ECM will determine that the throttle valve is malfunctioning and the ECM illuminates the MIL.

Refer to DTC P0120

NOTICE:

After replacing the ECM, the new ECM needs registration and initialization.

HINT:

After warming up the engine, DTC P0488 can be set if 1 second or more passes after quickly accelerating the engine from idling.

1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0488)

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch on (IG) and turn the tester ON.

3. Enter the following menus: Powertrain / Engine and ECT / DTC.

4. Read the DTCs.

   Result:

Display (DTC Output)	Proceed to
P0488	A
P0488 and P0120, P0122 and/or P0123	B

HINT:

If codes other than P0488 are output, perform troubleshooting for those DTCs first.

B	GO TO DTC CHART

A

2.CHECK IF DTC OUTPUT RECURS

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch on (IG) and turn the tester ON.

3. Enter the following menus: Powertrain / Engine and ECT / DTC / Clear.

4. Clear the DTCs.

5. Start the engine and accelerate the engine from idle to 3,000 rpm 3 times quickly.

6. Enter the following menus: Powertrain / Engine and ECT / DTC.

7. Read the DTCs.

Display (DTC Output)	Proceed to
P0488	A
No output	B

HINT:

The normal operation of the throttle valve is as follows.

Reference:

Condition	Throttle Valve Position
Moment when accelerator pedal is further depressed or released at 3,000 rpm	Opening angle varies smoothly

B	CHECK FOR INTERMITTENT PROBLEMS

A

3.CHECK WIRE HARNESS (DIESEL THROTTLE CONTROL MOTOR - ECM)

1. Disconnect the B33 throttle control motor connector.

2. Disconnect the B32 ECM connector.

3. Measure the resistance of the wire harness side connectors.

Standard resistance:

Tester Connection	Specified Condition
B33-1 (RSO) - B32-86 (LUSL)	Below 1 ?
B33-1 (RSO) or B32-86 (LUSL) - Body ground	10 k? or higher

4. Reconnect the throttle control motor connector.

5. Reconnect the ECM connector.

NG	REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

4.REPLACE DIESEL THROTTLE BODY ASSEMBLY (THROTTLE CONTROL MOTOR)

1. Replace the throttle body assembly.

NEXT

5.CHECK WHETHER DTC OUTPUT RECURS

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch on (IG) and turn the tester ON.

3. Clear DTCs.

4. Start the engine and drive the vehicle for approximately 15 minutes.

5. Enter the following menus: Powertrain / Engine and ECT / DTC.

6.  

Read the DTCs.

Display (DTC Output)	Proceed to
P0488	A
No output	B

B	SYSTEM IS OK

A
REPLACE ECM