PCM - MIL ON/DTC P0300/P0301 Engine Misfire
NO.: TSB-97-16-007DATE: July, 1997
MODEL: 1997 Montero Sport
SUBJECT:
DTC P0300/P0301 MISFIRE
PURPOSE
When driving at wide open throttle at about 5,000 engine rpm, the malfunction indicator lamp ("CHECK ENGINE") light may come on. Incorrect parameters programmed into the engine control module (ECM) will incorrectly judge this driving condition as a misfire, and set Diagnostic Trouble Code (DTC) P0300 or P0301.
A new, reprogrammed ECM is now available to prevent DTC P0300 or P0301 from being set under these driving conditions.
AFFECTED VEHICLES
1997 Montero Sport models produced before 3/6/97 (VIN VP018929)
PROCEDURE
If DTC P0300 or P0301 is set:
1. Verify that the vehicle VIN is before VP018929.
2. Confirm with the customer that the "CHECK ENGINE" light came on when driving at wide open throttle at about 5,000 rpm engine speed (approximately 45 mph).
3. Check the MUT-II freeze-frame data for engine speed at the time the DTC was set. Typically, false code P0300 or P0301 is set at about 5,000 rpm.
4. Check the ECM part number.
^ If the ECM part number is MD349088 or MD349089, STOP. Do not continue with this procedure. Refer to page 13A-416 of the 1997 Montero Sport service manual for troubleshooting instructions.
^ If the ECM part number is MD338138 or MD338139, continue with Step 5 below.
5. Replace the ECM, using the appropriate parts listed in the PARTS INFORMATION section of this bulletin.
PARTS INFORMATION
Description Part Number
ECM - Federal emission spec. models MD349089
ECM - Calif. emission spec. models MD349088
WARRANTY INFORMATION
ECM Replacement
Nature Code: 99D Cause Code: 990
Labor Operation No.13850310 Time Allowance: 0.5 hr.
Warranty Coverage: Emissions coverage
Special Warranty Information: Replace only as needed.