Toyota Celica 2005, Repair Manual

Page: 271 / 2497

DI − 72
− DIAGNOSTICS ENGINE (1ZZ − FE)
2005 CELICA (RM1131U)
MONITOR DESCRIPTION
If there is a defect in the MAF (Mass Air Flow) meter, or an open or short circuit, the voltage level will deviate
from the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets
a DTC.
Example:
The MAF meter voltage output is less than 0.2 V, or more than 4.9 V, and either condition continues for more
than 3 sec.
MONITOR STRATEGY
Related DTCs P0100
Mass air flow meter circuit range check
(Fluttering)
Mass air flow meter circuit range check
(Low voltage)
Mass air flow meter circuit range check
(High voltage)
Required sensors/components Mass air flow meter
Frequency of operation Continuous
Duration 3 sec.
MIL operation
Immediate (When engine speed is at less than 4,000 rpm)
2 driving cycles (When engine speed is at 4,000 rpm or more)
Sequence of operation None
TYPICAL ENABLING CONDITIONS
The monitor will run whenever this DTC is
not present
See page DI − 3
The typical enabling condition is not avail-
able
−
TYPICAL MALFUNCTION THRESHOLDS
Detection Criteria Threshold
Mass air flow meter circuit range check (Fluttering):
Mass air flow meter voltage Less than 0.2 V, or more than 4.9 V
Mass air flow meter circuit range check (Low voltage):
Mass air flow meter voltage Less than 0.2 V
Mass air flow meter circuit range check (High voltage):
Mass air flow meter voltage More than 4.9 V
COMPONENT OPERATING RANGE
Parameter Standard Value
Mass air flow meter voltage 0.4 to 2.2 V
270