Harsh, Soft, Delayed or Slipping 4-5-6 Shift

WARNING: This page is about a different variant/trim than selected.

Checks	Causes
NOTE: On cold days, approximately 32°F (0°C) or colder, the transmission is designed to shift differently. The transmission uses a warm-up mode shift schedule until the engine reaches normal operating temperature. While the transmission is in warm-up mode, it is normal for transmission upshifts to be delayed or held longer. This feature improves heater performance by giving quicker vehicle warm-ups.
Automatic Transmission Fluid Pan (29)	Verify proper fluid level and condition, inspect transmission assembly for leaks.
Control Valve Upper Body (304)	Inspect for sticking, damaged, or worn 1-R/4-5-6 clutch regulator valve (327) and spring (326). Inspect for damaged or sticking #3 and #4 ball check valves.
Control Valve Lower Body (307)	Inspect for worn, damaged, or sticking clutch select solenoid valve 2 (352) and valve spring (353).
Control Valve Solenoid Body (314)	Pressure Control Solenoid 3 commanded/failed HIGH (off) or leaking - Perform solenoid valve assembly function test. Refer to Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test . Incorrect or inadequate adapt activity - Perform Reset Transmission Adapts procedure.
4-5-6 Clutch (56)	Inspect for cut, worn, or damaged turbine shaft fluid seal rings (442). Inspect for damaged piston (439), piston dam (437), dam retaining ring (436), and clutch spring (438). Inspect for damaged or worn 4-5-6 clutch plates (432 - 435). Inspect for damage or leaking clutch housing (441). Inspect for improper selective 4-5-6 clutch backing plate retaining ring (431). Inspect for damaged or distorted turbine shaft.
Automatic Transmission Fluid Pump Seal (18)	Inspect for cut, leaking, or damaged seal.
4-5-6 Clutch Hub (58)	Inspect shaft for damage or wear. Inspect hub assembly (475), dampener (476), and apply plate (477) for wear or damage.
Automatic Transmission Fluid Pump Cover (219)	Inspect for damaged, stuck, sticky pressure regulator valve (233) and springs (234 and 235). Inspect for damaged, stuck, sticky isolator valve (236) and sleeve (237).