## Diesel Engine Management System

#### DTC Troubleshooting (cont'd)

11-106

DTC P1104: Incorrect MAF Low Range

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 P1104) being output?

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

NO – Go to step 3.

1. Start the engine at idling 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)?

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 +5V circuits for a 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 a short to ground.

Wire side of female terminals

MAF/IAT sensor 5P connector

Is a problem found?

YES – Repair the MAF B+ circuit.

NO – Go to step 10.

1. Connect the ECM connector.

a a a