Toyota Celica 2005 Repair Manual page 579

DI−380
3 Check for open in harness or ECM.
Mass Air Flow Meter
THA EVG
NG
Confirm good connection at ECM. If OK, re-
place ECM (See page SF−78).
4 Check for short in harness and ECM.
Mass Air Flow Meter
NG
2005 CELICA (RM1131U)
DIAGNOSTICS
PREPARATION:
(a) Remove the ECM cover.
ECM
(b) Connect between terminals THA and EVG of the ECM
connector.
THA
(c) Turn the ignition switch ON.
HINT:
E2
The mass air flow meter connector is disconnected. Before
checking, do a visual and contact pressure checks for the ECM
connector (See page IN−30).
(d) When using hand−held tester, enter the following menu:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL
DADA / INTAKE AIR.
CHECK:
Read the temperature value on the OBD II scan tool or hand−
A19548
held tester.
OK:
Temperature value: 140°C (284°F) or more
OK
PREPARATION:
(a) Disconnect the mass air flow meter connector.
ECM
(b) Turn the ignition switch ON.
(c) When using hand−held tester, enter the following menu:
THA
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL
DADA / INTAKE AIR.
E2
CHECK:
Read the temperature value on the OBD II scan tool or hand−
held tester.
A19550
OK:
Temperature value: −40°C (−40°F)
OK
− ENGINE (2ZZ−GE)
Repair or replace harness or connector.
Replace mass air flow meter.
578