PCM - MIL ON/DTC's P0304/P0306 Set

01-022

July 2, 2001

Applies To:
1998-99 3.0CL - ALL

MIL Comes On With DTCs P0304 and/or P0306

SYMPTOM

The MIL is on, and DTCs P0304 (Cylinder 4 misfire detected) and/or P0306 (Cylinder 6 misfire detected) are set.

PROBABLE CAUSE

The PCM may be detecting a false misfire.

CORRECTIVE ACTION

Do the diagnosis procedure in this service bulletin, and if needed, replace the PCM. Make sure you store your customer's immobilizer system key codes in the new PCM.

PARTS INFORMATION

Powertrain Control Module (California specification):
P/N 37820-P8A-L04

Powertrain Control Module (49-state specification):
P/N 37820-P8A-A04

WARRANTY CLAIM INFORMATION





In warranty:
The normal warranty applies.

Failed Part: P/N 37820-P8A-L03

Defect Code: 072

Contention Code: C99

Skill Level: Repair Technician

Out of warranty:
Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Parts and Service Manager or your Zone Office. You must request consideration, and get a decision, before starting work.

DIAGNOSIS

1. Use the PGM Tester to clear the DTC(s).

NOTE:
Make sure you clear the DTC(s) by selecting DTC/DATA CLEAR from the PGM-FI TEST MENU screen. Do not select ECM RESET from the PGM-FI TEST MENU screen or remove the PCM fuse. Using either of those methods would clear the PCM's long-term memory and abort the diagnosis procedure.

2. With the shift lever in Park, start the engine, and press down on the accelerator pedal until the engine speed is above 4,500 rpm. Slowly release the pedal until the speed drops to 4,500 rpm, then hold that speed for 1 minute. Release the pedal, and turn off the engine.

Does the MIL come on and are DTCs P0304 and/or P0306 set?

YES - Reset the PCM by now selecting ECM RESET from the PGM-FI TEST MENU screen, then go to step 3.

NO - Disregard this service bulletin, and continue with normal troubleshooting.

3. With the shift lever in Park, start the engine, and press down on the accelerator pedal until the engine speed is above 4,500 rpm. Slowly release the pedal until the speed drops to 4,500 rpm, then hold that speed for 1 minute. Release the pedal, and turn off the engine.

Does the MIL come on and are DTCs P0304 and/or P0306 set?

YES - Disregard this service bulletin, and continue with normal troubleshooting.

NO - Go to REPAIR PROCEDURE.

REPAIR PROCEDURE

1. Make sure you have the anti-theft code for the radio, and all of the working ignition keys (master and valet) for the vehicle. (This includes any master or valet keys with "T5" stamped on the shank or molded into the grip.)

2. Write down your customer's radio station presets.

3. Disconnect the negative cable from the battery.

4. Remove the passenger's door sill molding, and pull back the carpet.





5. Remove the PCM cover (four nuts).

6. Remove the PCM from the underside of the cover (three screws). Unplug the four electrical connectors.

7. Plug the electrical connectors into the new PCM. Install the PCM onto the cover.

8. Reinstall the PCM cover. Torque the nuts to 9.8 Nm (7.2 lb-ft).

9. Reinstall the carpet and the door sill molding.

10. Reconnect the negative battery cable.

11. Use the PGM Tester to store your customer's immobilizer system key codes in the PCM. Refer to S/B 00-019, Immobilizer System (Type 2), filed under Body Electrical.

12. Enter the anti-theft code for the radio.

13. Enter your customer's radio station presets. Reset the clock.





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