MIL ON - DTCs P0300 and P0306 (Misfire) Stored
June 7, 1999BULLENTIN NO.
99-020
YEAR
1996-97
MODEL
SLX
VIN APPLICATION
ALL
MIL On With DTCs P0300 Thru P0306 Stored
Symptom
The MIL is ON, and one or more engine misfire DTCs are stored.
PROBABLE CAUSE
The PCM (powertrain control module) sensed an intermittent engine misfire that may or may not be occurring.
CORRECTIVE ACTION
Retrieve the DTCs and record the DTC freeze data with the PGM Tester. Then update the PCM software according to Service Bulletin 99-019, Updating the SLX PCM, and correct any actual engine misfires.
REQUIRED TOOLS AND EQUIPMENT
PGM Tester with SN902 software or later For the other tools and equipment you'll need to update the PCM software, see Service Bulletin 99-019, Updating the SLX PCM, filed under Tools.
WARRANTY CLAIM INFORMATION
In warranty: The normal warranty applies.
Operation number: 121004
Flat rate time: 0.7 hour
Failed P/N: 8-16215-249-0
Defect code: 039
Contention code: C99
Template ID: 99-020A
Skill level: Repair Technician
Out of warranty: Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Technical Manager or your Zone Office. You must request consideration, and get a decision, before starting work.
REPAIR PROCEDURE
1. Make a copy of the PGM Tester Data form.
2. Retrieve any DTCs with the PGM Tester.
3. Record this information on the PGM Tester Data form:
- DTC(s) stored
- misfire history
- history data from output driver module 1
- engine freeze-frame data DTC failure records
- A/T freeze-frame data and DTC failure records
NOTE:
All DTCs and data records will be erased when you update the PCM software. If you don't write down the PGM Tester data, you won't be able to diagnose an actual misfire condition after you update the PCM.
4. Correct the causes of any non-misfire-related DTCs. For DTC troubleshooting information, refer to the 1996-1997 SLX Fuel and Emissions Manual.
5. Retrieve the PCM broadcast code with the PGM Tester or the Smart Cable (see Service Bulletin 99-019).
6. Compare the code you retrieved with the codes in the list below.
- If the code is in the list, update the PCM software with the Smart Cable. For instructions, see Service Bulletin 99-019, Updating the SLX PCM, filed under Tools. When you complete the PCM update, go to step 7.
- If the code is not in the list, the PCM software has already been updated. Go to step 7.
PCM Broadcast Codes:
BNTZ
BTPS, BTXF, BTXW, BTYB, BTXZ
BUWR, BUWS
BXCS, BXTF, BXTH
BYKJ
BZLJ
CDMW, CDNA, CDNK
7. Clear all DTCs with the PGM Tester.
8. Test-drive the vehicle with the PGM Tester connected. Use the PGM Tester Data form you filled out in step 3, and duplicate the conditions on the form by holding a steady throttle opening to maintain the same engine rpm and vehicle speed.
Freeze Data Interpretation Tips
- If the fuel level sensor voltage on the PGM Tester Data form was 2 V or more, a false misfire DTC probably occurred from running out of fuel.
- To find out how often a detected misfire DTC occurs, review the mileage since the last diagnostic test failed (FR LST FAIL on the PGM Tester Data form) and the elapsed time since the engine was started (RUN TIME on the form).
- If the ECT (engine coolant temperature) was below 1 76°F (80°C) on the form, the engine had not reached operating temperature. Before the test drive, let the engine cool down until it's below the temperature on the form.
- If the IAT (intake air temperature) on the form is higher than it is during the test drive, the engine was probably idling for a long time.
9. During your test drive, watch the misfire current counters on the PGM Tester.
- If the counters stay at zero, there are no detected misfires. Return the vehicle to the customer.
- If the counters increase, go to step 10.
10. Troubleshoot the detected misfire(s) using these sections of the 1996-97 SLX Fuel and Emissions Manual:
- OBD II Serviceability Issues:
* Fuel Quality
* Environment
* Vehicle Marshalling
* Severe Vibration
- DTC P0300 thru P0306 Troubleshooting
_ PCM Diagnostic Trouble Codes
For additional information, refer to these sections:
- Misfire Monitor Diagnostic Operation and Misfire Counters
- Malfunction Indicator Lamp
- Multiple PCM Information Sensor DTCs Set
- Engine Scan Tool Data Definitions and Ranges
- Typical Scan Data Values
PGM Tester Data: SLX with OBD II