TM 9-2320-363-20-1
Section 2
BASIC KNOWLEDGE REQUIRED (Contd.)
A diagnostic code indicates a problem in a given circuit (i.e., diagnostic Code 14 indicates a problem in the oil or coolant
temperature sensor circuit. This includes the oil or coolant temperature sensor, connector, harness and Electronic Control
Module (ECM)). The procedure for finding the problem can be found in Diagnosis Chart Code 14. Similar charts are
provided for each code. Remember, diagnosis should always begin at the starting chart (START). For an oil or coolant
temperature sensor problem, it will quickly lead you to Chart 14-but first gets you to verify the code/symptom.
Since the self-diagnostics do not detect all possible faults, the absence of a code does not mean there are no problems
in the system. If the DDEC II problem is suspected, even in the absence of a code, go to START anyway. This chart can
lead you to other charts which can aid in the troubleshooting process-where DDEC II problems may occur but do not
generate a code. Basic mechanical checks, however, are not covered in this guide.
F. USING THE MPSI READER
Plug the DDR into the 12 pin DDL connector.
Turn the ignition key to the ON position.
The reader will display the first 4 lines on the ECM Data. See area A. There are 54 lines of ECM Data.
You can scroll through the data one line at a time using the up or down arrow keys. You can also scroll through the data
4 lines at a time using the left or right arrow keys.
A line of data can be frozen on the screen by touching key numbers 1-4. Touching number 2 freezes data on line 2 of
the reader display. Touching the 2 again will unfreeze the data on line 2. If all 4 lines of data have been frozen, touching
the O key will unfreeze them.
The "FUNC" key allows the operator to move between ECM Data (menu A) and the function area (area 8). It also
allows movement from menu C to area "B".
The enter key is used to make a selection, confirm an answer, or instruct the DDR to continue to the next step.
A push button is located on the left side of the DDR. It is used to manually cut out individual cylinders when operating in
the cylinder cutout mode.
TO PERFORM ENGINE FUNCTIONS
Plug the DDR into the 12 pin DDL connector.
Turn the ignition key to the on position and allow the DDR to warm up.
Touch the "FUNC" key. You should now be in area B and the brackets should be around ENGINE.
Touch the ENTER key. This allows access to the features and data under the Engine Menu of area C. Use the up or
down arrow keys to scroll through the Engine Menu.
When you find the feature you want, touch enter and follow the instructions on the screen or use the up or down arrow
keys to scroll through the information on the screen.
If you wish to exit the Engine Menu touch the "FUNC" key. You should now be back in area B. To get back into ECM
Data touch the "FUNC" key once more.
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