Symptom Chart

SYMPTOM CHART

Condition	Possible Sources	Action
Transmission overheating	Excessive vehicle or towing loads, severe vehicle use	REFER to the vehicle specification manual for load and GVW/GCW information. REFER to the owner's guide.
	Incorrect fluid level	CHECK and, if necessary, ADJUST the fluid to the correct level. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 6HP26 article or AUTOMATIC TRANSMISSION - 6R75 article.
	Fluid condition	CHECK fluid condition. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 6HP26 article or AUTOMATIC TRANSMISSION - 6R75 article.
	Incorrect fluid type	REFER to Specifications.
	Transmission cooling system damaged, blocked, restricted or installed incorrectly	CARRY OUT the transmission fluid cooler flow test. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 6HP26 article or AUTOMATIC TRANSMISSION - 6R75 article.
	System leaks	REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 6HP26 article or AUTOMATIC TRANSMISSION - 6R75 article.
	Engine overheating	REFER to ENGINE COOLING article.
	Powertrain control system electrical inputs/outputs, vehicle wiring harnesses, powertrain control module (PCM), torque converter clutch (TCC) solenoid	CARRY OUT on-board diagnostics. REFER to the Introduction - Gasoline Engines article, and AUTOMATIC TRANSAXLE/TRANSMISSION - 6HP26 article or AUTOMATIC TRANSMISSION - 6R75 article.
	Internal transmission concerns	REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 6HP26 article or AUTOMATIC TRANSMISSION - 6R75 article.
Fluid leak at transmission in-tank cooler	Transmission fluid cooler fitting	REFER to the Component Test.