## Diesel Engine Management System

#### DTC Troubleshooting (cont'd)

11-102

DTC P1100: MAF sensor Supply Voltage High/Low

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 any other DTCs (beside DTC P0101) being output?

YES – Go to relevant DTC chart.

NO – Go to step 3.

1. Check for the following conditions:

- Damaged MAF sensor (A)
- The duct work at the MAF sensor for leaks
- PCV system vacuum leaks
- Incorrect PCV valve
- Vacuum leaks in EGR valve flange and pipes
- Intake manifold vacuum leaks

Is a problem found?

YES – Repair as necessary.

NO – Go to step 4.

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 indoor 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 6.

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 10.

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