GM Service Manual Online
For 1990-2009 cars only

4L60-E Transmission Fluid Checking Procedure

Step

Action

Value(s)

Yes

No

1

Check the fluid color.

Is the fluid color red?

--

Go to Step 2

Go to Step 11

2

Check the fluid level. Refer to Transmission Fluid Check

Is the fluid level satisfactory?

--

Go to Step 20

Go to Step 3

3

Check the fluid.

Is the fluid foamy?

--

Go to Step 8

Go to Step 4

4

Check the fluid level. The proper fluid level should be in the middle of the X-hatch.

Is the level high?

--

Go to Step 9

Go to Step 5

5

Fluid will be low.

Add fluid to the proper fluid level.

Is the fluid level satisfactory?

--

Go to Step 6

--

6

Check for external leaks. Refer to Fluid Leak Diagnosis and Repair

Did you find any leaks?

--

Go to Step 7

Go to Step 20

7

Correct the leak condition.

Did you correct the leak condition?

--

Go to Step 20

--

8

Is the fluid level too high?

--

Go to Step 9

Go to Step 10

9

Remove excess fluid to the proper fluid level.

Is the fluid level satisfactory?

--

Go to Step 20

--

10

  1. Check for contaminants in the fluid.
  2. Drain the fluid to determine the source of the contamination.

Did you drain the fluid?

--

Go to Step 15

--

11

Is the fluid color non-transparent pink?

--

Go to Step 12

Go to Step 13

12

Replace the cooler.

Is the replacement complete?

--

Go to Step 15

--

13

The fluid color should be light brown. Notice: Transmission fluid may turn dark with normal use. This does not always indicate oxidation or contamination.

Is the fluid color light brown?

--

Go to Step 14

--

14

Drain the fluid to determine if the fluid is contaminated.

Notice: A very small amount of material in the bottom pan is a normal condition, but large pieces of metal or other material in the bottom pan require a transmission overhaul.

Was the fluid contaminated?

--

Go to Step 15

Go to Step 18

15

Overhaul the transmission. Refer to the Unit Repair Section.

Is the overhaul complete?

--

Go to Step 16

--

16

Flush the cooler.

Has the cooler been flushed?

--

Go to Step 17

--

17

Add new fluid.

Is the procedure complete?

--

Go to Step 19

--

18

Change the fluid and the filter.

Is this procedure complete?

--

Go to Step 19

--

19

Is the fluid level satisfactory? Refer to Transmission Fluid Check

If not, correct as necessary.

--

Go to Step 20

--

20

Perform the Functional Test.

Is the Functional Test completed?

--

System OK

--