P0112-INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The PCM detects that the Intake Air Temperature Sensor input voltage is below the minimum acceptable value.

Possible Causes

INTERMITTENT DTC

(K21) IAT SIGNAL CIRCUIT SHORTED TO GROUND

(K21) IAT SIGNAL CIRCUIT SHORTED TO (K915) SENSOR GROUND

(K21) IAT SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

INTAKE AIR TEMPERATURE SENSOR

POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Diagnostic Test

1.DTC IS ACTIVE

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Is the status Active for this DTC?

Yes

Go to 2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2.(K21) IAT SIGNAL CIRCUIT SHORTED TO GROUND

Is the resistance above 100 ohms?

Yes

Go to 3

Repair the (K21) IAT Signal circuit for a short to ground.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

3.(K21) IAT SIGNAL CIRCUIT SHORTED TO (K915) SENSOR GROUND CIRCUIT

Is the resistance above 100 ohms?

Yes

Go to 4

Repair the (K21) IAT Signal circuit for a short to the (K915) Sensor Ground circuit.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

4.(K21) IAT SIGNAL CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE

Is the resistance below 5.0 ohms?

Yes

Go to 5

Repair the (K21) IAT Signal circuit for an open circuit or high resistance.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

5.INTAKE AIR TEMPERATURE SENSOR

Is the voltage above 4.5 volts with the Intake Air Temperature Sensor harness disconnected?

Yes

Replace the Intake Air Temperature Sensor in accordance with the service information.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

Go to 6

6.POWERTRAIN CONTROL MODULE (PCM)

Were any problems found?

Yes

Repair as necessary.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).

Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).