Inspection Procedure
HINT:
Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
- READ VALUE OF TECHSTREAM (MASS AIR FLOW RATE)
- Connect Techstream to the DLC3.
- Start the engine.
- Turn the tester on.
- On the tester, select the following menu items: Powertrain / Engine and ECT / Data List / MAF.
- Read the values displayed on the tester.
Result
DTC RESULT DESCRIPTION CHARTMass Air Flow Rate (g/sec) Proceed to 0.0 A 271.0 or more B Between 1.0 and 270.0 ((1)) C (1) The value must be changed when the throttle valve is open or closed.
B: Go to step 6
C : CHECK FOR INTERMITTENT PROBLEMS
A: Go to Next Step
- INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
- Disconnect the M1 Mass Air Flow (MAF) meter connector.
- Turn the ignition switch to the ON position.
- Measure the voltage between the terminal of the wire harness side connector and body ground.
Standard voltage
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions +B (M1-1) - Body ground Between 9 V and 14 V - Reconnect the MAF meter connector.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: Go to step 5
OK: Go to Next Step
- INSPECT ECM (VG VOLTAGE)
- Start the engine.
- Measure the voltage between the terminals of the E3 ECM connector.
HINT:
The transmission gear selector lever should be in the P or N position and the A/C switch should be turned OFF.
Standard voltage
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Conditions Specified Conditions VG (E3-30) - EVG (E3-29) Engine idling Between 0.5 V and 3.0 V
OK: REPLACE ECM
NG: Go to Next Step
- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
- Disconnect the M1 MAF meter connector.
- Disconnect the E3 ECM connector.
- Check the resistance.
Standard resistance (Check for open)
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions VG (M1-3) - VG (E3-30) Below 1 Ω E2G (M1-2) - EVG (E3-29) Below 1 Ω Standard resistance (Check for short)
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions VG (M1-3) or VG (E3-30) - Body ground 10 kΩ or higher - Reconnect the MAF meter connector.
- Reconnect the ECM connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE MASS AIR FLOW METER
- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI RELAY)
- Inspect the EFI2 fuse.
- Remove the EFI2 fuse from the engine room R/B.
- Check the EFI2 fuse resistance.
Standard resistance: Below 1 Ω
- Reinstall the EFI2 fuse.
- Remove the EFI relay from the engine room R/B.
- Disconnect the M1 MAF meter connector.
- Check the resistance.
Standard resistance (Check for open)
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions +B (M1-1) - EFI relay (3) Below 1 Ω Standard resistance (Check for short)
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions +B (M1-1) or EFI relay (3) - Body ground 10 kΩ or higher - Reconnect the MAF meter connector.
- Reinstall the EFI relay.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: INSPECT ECM POWER SOURCE CIRCUIT
- Inspect the EFI2 fuse.
- INSPECT ECM (SENSOR GROUND)
- Check the resistance.
Standard resistance
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions EVG (E3-29) - Body ground Below 1 Ω
NG: REPLACE ECM
OK: Go to Next Step
- Check the resistance.
- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
- Disconnect the M1 MAF meter connector.
- Disconnect the E3 ECM connector.
- Check the resistance.
Standard resistance (Check for open)
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions VG (M1-3) - VG (E3-30) Below 1 Ω E2G (M1-2) - EVG (E3-29) Below 1 Ω Standard resistance (Check for short)
TESTER CONNECTIONS AND SPECIFIED CONDITIONSTester Connections Specified Conditions VG (M1-3) or VG (E3-30) - Body ground 10 kΩ or higher - Reconnect the MAF meter connector.
- Reconnect the ECM connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE MASS AIR FLOW METER