NO.29 POOR VEHICLE ACCELERATION/PERFORMANCE [LA4AX-EL (CD4E)]


29	Poor vehicle acceleration/performance
POSSIBLE CAUSE	• Powertrain control system malfunction • Internal and external shift linkage malfunction • Torque converter clutch malfunction • Converter OWC malfunction


STEP	INSPECTION		ACTION
1	Powertrain control system • Are there any malfunctions with the following? - Engine - Electrical input/output - Vehicle wiring harness - PCM - Transaxle fluid temperature (TFT) sensor - Throttle position (TP) sensor - O/D OFF switch	Yes	Perform OBD test If the problem is engine related, go to the engine symptom troubleshooting (See ENGINE SYMPTOM TROUBLESHOOTING [YF (2.0L Zetec)].) (See ENGINE SYMPTOM TROUBLESHOOTING [AJ (3.0L Duratec)].) If the problem is not engine related, perform DTC troubleshooting (See AUTOMATIC TRANSAXLE ON-BOARD DIAGNOSTIC FUNCTION [LA4AX-EL (CD4E)].)
1		No	Go to the next step
2	Internal and external shift linkages • Do any of the following malfunctions exist? - Damaged - Misadjusted - Misassembled (See SELECTOR LEVER REMOVAL/INSTALLATION.)	Yes	Service if necessary
2		No	Go to the next step
3	Torque converter clutch • Is the torque converter clutch always applied?	Yes	Perform the Symptom Troubleshooting No.28 (See SYMPTOM TROUBLESHOOTING ITEM TABLE [LA4AX-EL (CD4E)].)
3		No	Go to the next step
4	Converter one-way clutch (OWC) • Is the converter OWC damaged?	Yes	Service if necessary
4		No	Perform the road test and verify the proper shift schedule and engagements Service if necessary (See ROAD TEST [LA4AX-EL (CD4E)].)
5	• Verify the test results. - If normal, return to the diagnostic index to service any additional symptoms. - If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. • If the vehicle is repaired, troubleshooting is completed. • If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.