## Diesel Engine Management System

#### DTC Troubleshooting (cont'd)

11-49

DTC P0102: MAF Sensor Circuit Low 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 P1625, P1618 or P0113 (beside DTC P0102) being output?

YES – Go to DTC P1625, P1618, or P0113 chart (5 V reference #1 circuit or ground circuit failure).

NO – Go to step 3.

1. Start the engine and allow it to idle.

1. Check the MAF with the scan tool.

Is about 8 – 13 g/sec indicated? (Sea level of 0 m at room temperature: about 20 °C.)

YES – Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the MAF sensor and at the ECM.

NO – Go to step 5.

1. Turn the ignition switch OFF.

1. Disconnect the MAF sensor 5P connector.

1. Disconnect ECM connector.

1. Check the MAF sensor signal and +5 V circuits for an open or short to ground.

Wire side of female terminals

MAF/IAT sensor 5P connector

JUMPER WIRE

Is a problem found?

YES – Repair the MAF signal or +5 V circuit.

NO – Go to step 9.

1. Check the MAF sensor B+ circuit for an open or short to ground.

Wire side of female terminals

MAF/IAT sensor 5P

Is a problem found?

YES – Repair the MAF +B circuit.

NO – Go to step 10.

1. Connect the ECM connector.

1. Connect the MAF sensor 5P connector terminals No. 4 and No. 5 with a jumper wire.

Wire side of female terminals

MAF/IAT sensor 5P connector

JUMPER WIRE

1. Turn the ignition switch ON (II).

a a a