Road Testing

Prior to performing a road test, check the fluid level.

During the road test, the transaxle should be operated in each position to check for slipping and any variation in shifting. During test drive the transmission sump temperature should be monitored for normal values. Sump temperatures in excess of 230° F should prompt a thorough oil level and cooling systems check. RPM monitors should also be watched for lock-up and gear shifting.

If vehicle operates properly at high speeds, but has poor acceleration, the converter's overrunning clutch may be slipping. If acceleration is normal, but high throttle opening is needed for high speeds, the clutch may have seized. Both of these stator defects require replacement of the torque converter.

The clutch that is slipping can be determined by checking for a DTC code 50-54 and noting the transaxle operation in all selector positions. Then comparing which internal units are applied in those positions. The Elements in Use Chart provides a basis for road test analysis.

The process of elimination can be used to detect any unit which slips and to confirm proper operation of good units. Road test analysis can usually diagnose slipping units. However, the actual cause of the malfunction may not be detected. Practically any condition can be caused by leaking hydraulic circuits or sticking valves.