MIL ON - DTC's P0300 Thru P0304 Set

Article No.
01-4-13

03/05/01

^ DRIVEABILITY - ROUGH IDLE, LOW POWER
AND/OR STALL AT IDLE - DIAGNOSTIC TROUBLE
CODES (DTCS) P0300 - P0304 STORED IN
MEMORY - MALFUNCTION INDICATOR LAMP (MIL)
ILLUMINATED - VEHICLES EQUIPPED WITH 2.0L
SRI ENGINE ONLY

^ MALFUNCTION INDICATOR LAMP (MIL)
ILLUMINATED - LOW POWER, ROUGH IDLE
AND/OR STALL AT IDLE - DIAGNOSTIC TROUBLE
CODES (DTCS) P0300-P0304 STORED IN
MEMORY - VEHICLES EQUIPPED WITH 2.0L SRI
ENGINE ONLY

^ ELECTRICAL - LAMP - MALFUNCTION INDICATOR
LAMP (MIL) ILLUMINATED - DIAGNOSTIC TROUBLE
CODES (DTCS) P0300 - P0304 STORED IN
MEMORY - LOW POWER, ROUGH IDLE AND/OR
STALL AT IDLE-VEHICLES EQUIPPED WITH 2.0L
SPI ENGINE ONLY

FORD:
2000-2001 FOCUS

ISSUE
Some vehicles equipped with the 2.0L SPI engine may exhibit a Malfunction Indicator Lamp (MIL) illuminated and Diagnostic Trouble Codes (DTCs) P0300 through P0304 stored in memory. The vehicle may also have a rough idle or reduced power condition, and/or may stall at an idle. This may be caused by sticking exhaust valves due to excessive carbon build-up.

ACTION
Check for faulty fuel injectors and ignition wires. One or more exhaust valves may be temporarily sticking due to carbon build-up between the valve stem and guide. If the diagnostic checks point to a sticking exhaust valve, the cylinder head assembly may need to be replaced with a new level cylinder head assembly that includes revised valve guides to help prevent carbon build-up. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

NOTE
THIS PROCEDURE APPLIES ONLY TO THE 2.0L SPI ENGINE.

This condition usually results in misfire when the engine returns to idle after running over approximately 2000 rpm.

1. Use the Worldwide Diagnostic System (WDS) to test for Power Balance with the engine at idle. Check for cylinder misfire. If misfire is occurring constantly, go to Step 3. If misfire is not occurring, attempt to induce misfire by performing the following step:

a. Apply the parking brake and keep the transmission in Park or Neutral. Bring the engine to approximately 2800 rpm and hold for 1 minute. Check the WDS Power Balance display while holding engine speed constant. Let the engine return to idle and watch the WDS Power Balance display for a misfiring cylinder.

2. If WDS Power Balance indicates a misfiring cylinder with the previous test, one or more exhaust valves may be intermittently sticking due to carbon build-up between the valve stem and guide. Replace the cylinder head and cam assembly with a new level cylinder head and cam assembly built with revised valve guides to help prevent carbon build-up. Consult the appropriate model year Workshop Manual for removal and installation procedures for the cylinder head and cam assembly.

3. If WDS Power Balance did not indicate a misfiring cylinder with the previous test or a misfire is occurring constantly, the misfire may not be due to a sticking exhaust valve. Refer to the appropriate model year Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual for further diagnosis. Other possible causes may be, worn or arcing ignition wires, base engine compression, fuel injectors, fuel injector harness resistance or PCM injector driver signal. Perform diagnosis and repair as necessary.

4. After completing either Step 2 or Step 3, replace the PCV Valve (YS4Z-6A666-AA (Motorcraft EV-244)). Vacuum fluctuations from engine misfire may prematurely wear the PCV valve.

The following is a list of parts that may be required.





Parts Block

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: INFORMATION ONLY

OASIS CODES: 499000, 607000, 607400, 607500, 607600, 607700, 608000, 608400, 608500, 608600, 609000, 609400, 609500, 609600, 611000, 611500, 614000, 614500, 614600, 698298