Inspection Procedure

HINT:

If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
Read freeze frame data using the intelligent 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.

READ VALUE OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)

Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
Turn the ignition switch ON and turn the intelligent tester ON.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
Read the values.
Standard: Same as actual Intake Air Temperature (IAT).

Result

RESULT CHART

Intake Air Temperature	Proceed to
-40°C (-40°F)	A
140°C (284°F) or more	B
OK (same as present temperature)	C

HINT:

If there is an open circuit, the intelligent tester indicates -40°C (-40°F).

If there is a short circuit, the intelligent tester indicates 140°C (284°F) or more.

B: GO TO step 4

C: CHECK FOR INTERMITTENT PROBLEMS

A: GO TO Next Step

READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
1. Disconnect the M1 Mass Air Flow (MAF) meter connector.
2. Connect terminals THA of the MAF meter wire harness side connector.
3. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
4. Turn the ignition switch ON and turn the intelligent tester ON.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
6. Read the value.
  Standard: 140°C (284°F) or more
OK: CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER

Fig 1: Checking M1 Mass Air Flow (MAF) Meter Connector For Open In Wire Harness
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO Next Step
READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN ECM)
1. Disconnect the M1 MAF meter connector.
2. Connect terminals THA and E2 of the E5 ECM connector.
  HINT:
  
  Before checking, do a visual and contact pressure check for the ECM connector.
3. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
4. Turn the ignition switch ON and turn the intelligent tester ON.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
6. Read the value.
  Standard: 140°C (284°F) or more
NG: CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM

Fig 2: Checking M1 Mass Air Flow (MAF) Meter Connector For Open In ECM
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the M1 MAF meter connector.
2. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
3. Turn the ignition switch ON and turn the intelligent tester ON.
4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
5. Read the value.
  Standard: -40°C (-40°F) or more
OK: REPLACE MASS AIR FLOW METER

Fig 3: Identifying MAF Meter Circuit
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO Next Step
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN ECM)
1. Disconnect the M1 MAF meter connector.
2. Disconnect the E5 ECM connectors.
3. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
4. Turn the ignition switch ON and turn the intelligent tester ON.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
6. Read the value.
  Standard: -40°C (-40°F) or more
NG: REPLACE ECM

Fig 4: Identifying MAF Meter Circuit With E5 ECM Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR