On-Vehicle Inspection

WARNING: This page is about a different car, the 2007 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT AIR-FUEL RATIO COMPENSATION SYSTEM

Measure the voltage between the terminals of the ECM connectors.

Standard

TESTER CONNECTION AND SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
B22 (A1A+) - A28 (E2)	Ignition switch ON	3.3 V
B23 (A2A+) - A28 (E2)	Ignition switch ON	3.3 V
B30 (A1A-) - A28 (E2)	Ignition switch ON	2.9 V
B31 (A2A-) - A28 (E2)	Ignition switch ON	2.9 V

NOTE: Connect test leads from the back side of the connector. Do not disconnect the connectors from the ECM.

HINT:

Voltage between the terminals of the ECM is kept constant regardless of the voltage of the A/F sensor.

Fig 1: Measuring Voltage Between Terminals Of ECM Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / A/FS B1 S1 and O2S B1 S2.
Warm up the A/F sensor with the engine speed at 2,500 rpm for approximately 2 minutes.

Fig 2: Connecting Intelligent Tester To DLC3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Maintain the engine speed at 2,500 rpm and confirm that the display on the intelligent tester, when A/FS B1 S1 is selected, is as shown in Fig 3.
HINT:
- The illustration may slightly differ from the display on the intelligent tester.
- Only the intelligent tester displays the waveform of the A/F sensor.
Confirm that the waveform displayed on the intelligent tester, when O2S B1 S2 is selected, changes between 0 V and 1 V with the engine speed at 2,500 rpm.
OK: The voltage output oscillates more than 8 times in 10 seconds.

Fig 3: Engine Speed Output Voltage Graph
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CAUTION:
- Perform the check immediately after warming up the engine.
- If the voltage variation could not be verified, warm up the heated oxygen sensor again. If it could not be verified even after warming up the sensor again, check the DTC No. (see DTC P0136 OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 1 SENSOR 2); DTC P0137 OXYGEN SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2); DTC P0138 OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 2); DTC P0156 OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 2 SENSOR 2); DTC P0157 OXYGEN SENSOR CIRCUIT LOW VOLTAGE (BANK 2 SENSOR 2); DTC P0158 OXYGEN SENSOR CIRCUIT HIGH VOLTAGE (BANK 2 SENSOR 2) ).

INSPECT FUEL CUT OFF RPM
1. Increase the engine speed to at least 3,500 rpm.
2. Use a sound scope to check for injector operating sounds.
3. Check that injector operating sounds stop momentarily and then resume when the accelerator pedal is released.
  Fuel cut off rpm: 2,500 rpm
  
  Fuel return rpm: 1,400 rpm
VISUALLY INSPECT HOSES, CONNECTIONS AND GASKETS
1. Check the appearance.
  1. Check if the indicated portions of the engine assembly are cracked, leaking or damaged.
    HINT:
    
    Disconnection of the engine oil level gauge, oil filler cap, PCV hose, etc. may cause the engine to run improperly. Disconnected, loose or cracked parts in the air induction system between the throttle body and cylinder head will allow air suction and cause the engine to run improperly.
    
    Fig 4: Identifying Engine Assembly Cracked, Leaking Or Damaged Hoses
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    If necessary, repair the engine assembly.
INSPECT FUEL CUTOFF VALVE AND FILL CHECK VALVE
1. Remove the fuel tank (see REMOVAL ).
2. Connect the pressure gauge to the vent hose port.
3. Install the fuel tank with the vent hose disconnected.
4. Fill the fuel tank with fuel.
5. Apply pressure at 4 kPa (41 gf/cm² , 0.58 psi) to the vent port of the fuel tank.
  HINT:
  
  Check the amount of fuel left in the fuel tank.
  
  Fig 5: Connecting Pressure Gauge To Vent Hose Port
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Remove the fuel tank cap, and check that the pressure decreases.
  If the pressure does not decrease, replace the fuel tank assembly.
7. Reconnect the vent line hose to the fuel tank.
  
  Fig 6: Removing Fuel Tank Cap
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CHECK AIR INLET LINE
1. Disconnect the air inlet line hose from the charcoal canister.
2. Check that air flows freely into the air inlet line. If air does not flow freely into the air inlet line, repair or replace the air inlet line.
3. Reconnect the air inlet line hose to the charcoal canister.
  
  Fig 7: Disconnecting Air Inlet Line Hose From Charcoal Canister
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT LEAK DETECTION PUMP (Pressure Sensor)

Measure the power source voltage of the ECM connectors.

Standard

TESTER CONNECTION AND SPECIFIED CONDITION REFERENCE

Tester Connection	Condition	Specified Condition
A23 (VC) - A28 (E2)	Ignition switch ON	4.5 to 5.5 V

If the voltage is not as specified, check the ECM, leak detection pump and wire harness.

Measure the power output of the ECM connectors.

Remove the fuel tank cap.

Standard

TESTER CONNECTION AND SPECIFIED CONDITION REFERENCE

Tester Connection	Condition	Specified Condition
E22 (PPMP) - A28 (E2)	Ignition switch ON	1.425 to 4.150 V

If the voltage is not as specified, check the ECM, leak detection pump and wire harness.

Install the fuel tank cap.

Fig 8: Leak Detection Pump Output Voltage Graph
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002