1. Ensure the transmission shift select is in the PARK position.
2. Turn the ignition switch to the OFF position for 6 seconds.
3. Turn the ignition switch to the RUN position and note the three transfer case shift select buttons.

Do all three shift select buttons blink once?

Go to Step 2

Refer to Functional Test Failed Step 2

Did one of the shift select buttons stay lit in order to indicate the transfer case shift position?

Go to Step 3

Refer to Functional Test Failed Step 4

1. Shift the transfer case to 4HI.
2. Shift the transfer case to 2HI.
3. shift the transfer case back to 4HI.

Does the transfer case mode shift between 4HI and 2HI?

Go to Step 4

Refer to Functional Test Failed Step 6

1. Apply the park brake.
2. For automatic transmissions, place the transmission shift select in the PARK position.
3. For manual transmissions, shift the transmission into first gear.
4. Place the ignition switch in the RUN position.
5. Place the transfer case in the 4HI position.
6. Press the 4LO transfer case shift select button.

Does the 4LO shift select button blink for 30 seconds and the stop blinking when the 4HI shift select button illuminates?

Go to Step 5

Refer to Functional Test Failed Step 8

1. Place the ignition switch in the RUN position.
2. Place the transfer case in the 4HI position.
3. Press the 4Lo transfer case shift select button and note the blinking.
4. For automatic transmissions, position the transmission shift select to NEUTRAL.
5. For manual transmissions, push the clutch pedal to the floor panel.

Does the 4LO shift select button stop blinking and stay lit when the transmission is shifted to neutral (for automatic transmissions) or the clutch pedal is pushed in (for manual transmissions)?

Go to Step 6

Refer to Functional Test Failed Step 8

1. Press the 2HI shift select button and shift the transfer case into 2HI.
2. For automatic transmissions, position the transmission shift select in the PARK position.
3. For manual transmissions, position the transmission into the first gear.
4. Position the ignition switch to OFF.
5. Using a wire, connect pin 13 on the data link connector to a vehicle ground source.
6. Position the ignition switch to RUN.

Do all three shift select buttons blink once and then stay OFF?

Test complete transfer case electronic shift system operates properly.

Refer to Functional Test Failed Step 9