P0112

DTC P0112: Intake Air Temp. (IAT) Circuit Low Input

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

NOTE:

Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temperature: -14 °C, 6.8 °F or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 10 sec.
4) Check DTC and pending DTC.

DTC Troubleshooting

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. IAT sensor and its circuit check.

Connect scan tool with ignition switch turned OFF.
Turn ON ignition switch.
Check intake air temp. displayed on scan tool.

Is 205 °C (401 °F) indicated?
YES
Go to Step 3.
NO
Intermittent trouble.
Check for intermittent referring to Intermittent and Poor Connection Inspection.

3. Check ECM voltage.

Disconnect connector from IAT sensor with ignition switch turned OFF.
Check proper connection to IAT sensor at "LT GRN/BLK" and "ORN" wire terminals.
If OK, then turn ON ignition switch, check voltage between "LT GRN/BLK" wire terminal and vehicle body ground.

Is voltage about 4 - 6 V at each terminal?
YES
Go to Step 6.
NO
Go to Step 4.

4. Check IAT circuit insulation.

Disconnect connectors from ECM with ignition switch turned OFF.
Measure resistance between "LT GRN/BLK" wire terminal and body ground.

Is resistance infinity?
YES
Go to Step 5.
NO
"LT GRN/BLK" wire shorted to ground circuit.
If wire are OK, substitute a known-good ECM and recheck.

5. Check IAT short circuit.

Turn ON ignition switch.
Check voltage between "LT GRN/BLK" wire terminal and vehicle body ground.

Is voltage about 0 V at each terminal?
YES
Go to Step 6.
NO
"LT GRN/BLK" wire shorted to other circuits.
If wire are OK, substitute a known-good ECM and recheck.

6. Check IAT sensor.

Check IAT sensor according to Intake Air Temperature (IAT) Sensor Inspection Intake Air Temperature (IAT) Sensor Inspection.

Is it good condition?
YES
Substitute a known-good ECM and recheck.
NO
Replace IAT sensor.