Service Procedure

Figure 1:

1. Check for a white, round label marked "ECM" (Figure 1) affixed to the inside of the driver's door.

a. If an "ECM" label is present, ECM replacement is not necessary. DO NOT continue with this Service Procedure.

b. If an "ECM" label is not present, continue with this Service Procedure.

2. Replace the Electronic Control Module (ECM) as follows:

a. Disconnect the battery terminals.

b. Remove the engine hood release and its cable.


c. Remove the switcb bezel and cigarette lighter bezel from the instrument panel. Use care to prevent damaging the bezel tabs.

- Disconnect all of the connectors at the rear of each bezel.

d. Remove the knee pad as described in the appropriate Workshop Manual.

e. Remove the ventilator vent.

f. On Impulse models equipped with automatic transmission, remove the transmission control unit (TCM).

g. Remove the ECM and its bracket. Inspect the part number on the removed ECM.

IMPORTANT If the ECM part number matches one of the part numbers listed in the "Parts Information" section of this Bulletin, DO NOT CONTINUE with this campaign procedure.


Remove the two clip-type studs on the side of the ECM case.

h. Install a new ECM (see "Parts Information" in this Bulletin), using the two clip-type studs removed from the old ECM, and the old ECM bracket.

i. On Impulse A/T models, reinstall the TCM.

j. Reinstall the ventilator vent.

k. Reinstall the knee pad as described in the appropriate Workshop Manual.

l. Reinstall the switch bezel, cigarette lighter bezel, and their connectors.

m. Reinstall the engine hood release and its cable.

n. Reconnect the battery terminals.

3. Install a jumper wire between pins I and 3 of the white ALDL connector. Turn the igriition key to "ON" for about five seconds. Do not crank the engine. Verify that the "CHECK ENGINE"


lamp displays Code 12. Then turn the key to "OFF" and remove the jumper wire.

4. Start the engine. Verify that the "CHECK ENGINE" lamp comes on, then goes out.

a. If the "CHECK ENGINE" lamp remains on, disconnect and reconnect the battery terminals, and repeat step 3 above.

b. If the "CHECK ENGINE" lamp remains on after repeating step 3, check for failure codes (displayed by "CHECK ENGINE" lamp, or by using the Tech 1 diagnostic scan tool). Make the appropriate repairs as required by the failure code(s).


5. Check to ensure that the cigarette lighter and the switch bezel functions operate properly.

6. Affix a campaign label to the radiator core support, in a visible area. Using a ball-point pen, fill in the label with the Campaign number (91-E-355) and dealer code.

DEALER RESPONSIBILITY

Isuzu dealers are responsible for repairing any affected vehicle regardless of date of purchase, mileage or selling dealer.


FLAT RATE MANUAL INFORMATION


OPERATION
OPERATION NUMBER TASK THM

Control Unit (ECM)
Campaign Replacement 03A210 Replace 0.5


Use Trouble Code 07 for all Campaign operations.