Diagnostic Test Mode 4

Diagnostic Test Mode 4

DTM 4 activates the same components/functions activated in DTM 3 but activation takes place component by component, only as requested by the operator. The component/function is activated six times in sequence.

In DTM 4 the rate of code transmission between the transmission control module TCM and the DLC can be changed from two to ten times the standard rate.

After testing, the OBD system automatically exits test function 4. This means that to perform another test, the entire procedure must be repeated from the beginning. DTM 4 is activated with four short presses on the DLC button.

Activating Diagnostic Test Mode 4

NOTE: On cars with Turbo and/or OBD II. When activating DTCs 4-3-1 and 4-3-2 no change/sympton is indicated on the engine, transmission or combined instrument. To check these functions proceed as follows before activating DTM 4:

- Ignition OFF
- Connect testbox
- Connect a voltmeter to the terminals indicated in the table below. Check the voltmeter reading when function is activated.






- Ignition ON
- Move the gear selector to position P or N.
- Engine idling (applies to activating DTCs 4-1-4, 4-2-2 and 4-2-3).

NOTE: The gear selector must be in position P or N and the car's speed should be 0 km/h.






- Press the DLC button four times.
- Enter the selected code. Enter one digit each time the LED comes on.

LED begins flashing when the component/function is activated.

Use a stethoscope to listen for solenoid clicks. The following components/functions can be activated: