Personality Module

TM 9-2320-312-24-2

Troubleshooting Section

4. Verify that the ECM is receiving battery voltage

when the ignition key switch is turned on. Refer

to Troubleshooting, "Ignition Key Switch Circuit

and Battery Supply Circuit - Test".

5. Connect a bypass circuit for the ECM. Refer to

Illustration 19.

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Illustration 19

Personality Module

2. Ensure that the hydraulic electronic unit injector

connector (J300/P300) is fully connected and

ensure that the hydraulic electronic unit injector

A new ECM has a Personality Module that is not

connector (J300/P300) is free of corrosion.

programmed. The engine will not start until the

Personality Module has been flashed. Also, the

3. Check for logged diagnostic codes that are

engine will not communicate until the Personality

related to the cylinder. Go to Troubleshooting,

Module has been flashed.

"Injector Solenoid Circuit - Test" if diagnostic

codes that are related to the cylinder are present.

ECM

Engine Speed/Timing Signal

Before replacing the ECM, try to flash program

the existing ECM. Refer to Troubleshooting, "Flash

Programming".

1. Check the engine speed/timing signal.

If the ECM is suspected of being the problem,

2. Observe the engine rpm with the electronic

temporarily connect a test ECM. This will show

service tool while the engine is being cranked.

whether the problem has been resolved or the

problem has not been resolved.

This may require the electronic service tool to

be powered directly by the vehicle batteries or

this may require the electronic service tool to be

Hydraulic Electronic Unit Injectors

powered directly by a separate power source

(12 VDC). Refer to Illustration 19.

1. Check the electrical connections to the hydraulic

electronic unit injectors.