Inspection Procedure

HINT:

It is possible to find the malfunctioning area using the ACTIVE TEST A/F CONTROL operation. The ACTIVE TEST can determine if the HO2S or other potential trouble areas are malfunctioning or not.

The injection volume can be switched to -12.5% (decrease) or +25% (increase) by the ACTIVE TEST.

The ACTIVE TEST procedure enables a technician to check and graph the voltage outputs of the HO2Ss.

Procedure:

Connect the hand-held tester to the DLC3.
Turn the ignition switch ON.
Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
Perform the ACTIVE TEST while the engine is idling.

Standard:

The HO2S reacts in accordance with increase and decrease of injection volume:

+25% --> RICH output: More than 0.55 V,

-12.5% --> LEAN output: Less than 0.4 V

NOTE: The HO2S (sensor 1) output has a few seconds of delay and the HO2S (sensor 2) output has a maximum of 20 seconds of delay.
If the vehicle is short on fuel, the air-fuel ratio becomes LEAN and the DTCs will be recorded.

Fig 1: Injection Volume Voltage Specifications Table

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was LEAN or RICH, and other data from the time the malfunction occurred.

CHECK OTHER DTC OUTPUT

Connect the hand-held tester to the DLC3.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
Read the DTCs.

Result:

RESULT DESCRIPTION

Display (DTC output)	Proceed to
P0134 or P0154	A
P0134 or P0154 and other DTCs	B

B: Go to RELEVANT DTC TABLE (See DIAGNOSTIC TROUBLE CODE TABLE )
A: Go to next step.

READ DATA LIST (HO2S (SENSOR 1) VOLTAGE)
1. Connect the hand-held tester to the DLC3.
2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY f/ O2S B1S1 (O2S B2S1).
3. Allow the engine to idle until the ECT reaches 40°C (104°F).
4. Quickly depress the accelerator pedal 3 times until the engine RPM reaches 4,000 rpm. Then, read the HO2S (sensor 1) voltage.
  Standard: HO2S (sensor 1) voltage is 0.45 V or more at least once.
1. OK: Go to step 11 .
2. NG: Go to next step.
CHECK CONNECTION OF PCV HOSE
OK: PCV hose is connected correctly and is not damaged.
1. NG: REPAIR OR REPLACE PCV HOSE
2. OK: Go to next step.

INSPECT HEATED OXYGEN SENSOR

Disconnect the H9 and H10 HO2S connectors.
Measure the resistance of the HO2Ss.

Standard:

RESISTANCE SPECIFICATIONS

Tester Connection	Specified Condition
1 (HT) - 2 (+B)	5 to 10 ohms at 20°C (68°F)
1 (HT) - 4 (E1)	10 k ohms or higher

Fig 2: Identifying H9 & H10 HO2S Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE HEATED OXYGEN SENSOR
OK: Go to next step.

INSPECT RELAY (Marking: EFI)

Remove the EFI relay from the engine room No. 2 R/B.
Measure the resistance of the relay.

Standard:

RESISTANCE SPECIFICATIONS

Tester Connection	Specified Condition
3 - 5	10 k ohms or higher
3 - 5	Below 1 ohms (when battery voltage is applied to terminals 1 and 2)

Fig 3: Identifying Relay (Marking EFI)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE RELAY
OK: Go to next step.

CHECK WIRE HARNESS (HO2S - ECM)

Disconnect the H9 and H10 HO2S connectors.
Disconnect the E3 and E4 ECM connectors.
Measure the resistance of the wire harness side connectors.

Standard:

RESISTANCE SPECIFICATIONS

Tester Connection	Specified Condition
H9-1 (HT) - E3-9 (HTL)	Below 1 ohms
H9-3 (OX) - E3-28 (OXL1)	Below 1 ohms
H10-1 (HT) - E4-30 (HTR)	Below 1 ohms
H10-3 (OX) - E4-28 (OXR1)	Below 1 ohms
H9-1 (HT) or E3-9 (HTL) - Body ground	10 k ohms or higher
H9-3 (OX) or E3-28 (OXL1) - Body ground	10 k ohms or higher
H10-1 (HT) or E4-30 (HTR) - Body ground	10 k ohms or higher
H10-3 (OX) or E4-28 (OXR1) - Body ground	10 k ohms or higher

Fig 4: Identifying H9 & H10 HO2S Connector Terminals

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step.

CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leaks.
  OK: There is no vacuum leaks in air induction system.
1. NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM
2. OK: Go to next step.
CHECK FUEL PRESSURE (See ON-VEHICLE INSPECTION )
1. NG: REPAIR OR REPLACE FUEL SYSTEM
2. OK: Go to next step.
INSPECT FUEL INJECTOR ASSY (See INSPECTION )
1. NG: REPLACE FUEL INJECTOR ASSY (See REPLACEMENT )
2. OK: Go to next step.
CHECK FOR EXHAUST GAS LEAKAGE
1. NG: REPAIR OR REPLACE EXHAUST SYSTEM
2. OK: REPLACE HEATED OXYGEN SENSOR
PERFORM CONFIRMATION DRIVING PATTERN
HINT:

Clear all DTCs prior to performing the confirmation driving pattern.
1. NEXT: Go to next step.

READ OUTPUT DTC (DTC P0134 OR P0154 IS OUTPUT AGAIN)

Clear the DTC (see DTC CHECK/CLEAR ).
Start the engine and allow the engine to idle for 15 seconds or more.
Read the DTC.

Result:

RESULT DESCRIPTION

Display (DTC output)	Proceed to
None	A
P0134 or P0154	B

B: REPLACE ECM (See REPLACEMENT )
A: Go to next step.

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
1. If the vehicle has run out of fuel, proceed to A.
2. If the vehicle has not run out of fuel, proceed to B.
1. B: See CHECK FOR INTERMITTENT PROBLEMS
2. A: DTC IS CAUSED BY RUNNING OUT OF FUEL