## Diesel Engine Management System

#### DTC Troubleshooting (cont'd)

11-54

DTC P0113: IAT Sensor Circuit High Voltage

1. Check the ''On Board Diagnostic (OBD) System Check''.

Was the ''OBD System Check'' performed?

YES – Go to step 2.

NO – Go to OBD System Check.

1. Check the DTC.

Are there other DTCs (P0101/P0103) being output?

YES – Go to step 3.

NO – Go to step 8.

1. Turn the ignition switch OFF.

1. Disconnect the IAT sensor 5P connector.

1. Disconnect ECM connector.

1. Check the IAT sensor signal and ground circuits for an open.

Wire side of female terminals

MAF/IAT sensor 5P connector

JUMPER WIRE

Is a problem found?

YES – Repair the IAT/MAF signal or ground circuit.

NO – Go to step 7.

1. Connect the IAT/MAF sensor 5P connector and the ECM connector.

1. Turn the ignition switch ON (II).

1. Check the IAT with the scan tool.

Is about 215°C (419°F) indicated?

YES – Go to step 10.

NO – Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the IAT sensor and at the ECM.

1. Turn the ignition switch OFF.
2. Disconnect the IAT sensor 5P connector.

1. Connect the IAT sensor 5P connector terminals No. 1 and No. 3 with a jumper wire.

Wire side of female terminals

MAF/IAT sensor 5P connector

JUMPER WIRE

1. Turn the ignition switch ON (II).

1. Check the IAT with the scan tool.

Is there more than 120°C (248°F)?

YES – Replace the IAT/MAF sensor.

NO – Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.

NOTICE

The battery power supply short circuit to 5 V power supply damages the ECM.

a a a