GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Start the engine and allow the engine to idle until the transmission has reached the value specified.
  2. Depress the brake pedal and move the shift lever through the gear ranges, pausing a few seconds in each gear.
  3. Pull dip stick and check fluid sample for color.

82-93°C

(180-200°F)

Go to Step 4

Go to Step 2

2

Check the fluid level. The vehicle must be level, with the engine running and the shift lever in the PARK range. Check both sides of the fluid level indicator, and read the lower level. The proper fluid level should be in the middle of the X-hatch.

Is the fluid level too high?

--

Go to Step 9

Go to Step 3

3

Does the fluid have a burnt odor or a dark brown color?

--

Go to Step 11

Go to Step 4

4

Does the fluid have a cloudy or milky appearance?

--

Go to Step 10

Go to Step 5

5

Is the fluid level low?

--

Go to Step 6

System OK

6

Add DEXRON® III automatic transmission fluid in increments of 0.5 L (0.5 qt) until the fluid is in the middle of the X-hatch. Check both sides of the fluid level indicator, and read the lower level.

Did you add more than 1.5 L (1.6 qt) to the transmission?

--

Go to Step 7

Go to Step 9

7

Check for external leaks. Refer to Fluid Leak Diagnosis .

Did you find any leaks?

--

Go to Step 8

Go to Step 15

8

Correct the leak condition.

Did you correct the leak condition?

--

Go to Step 15

--

9

Remove any excess fluid to the proper level, the middle of the X-hatch.

Is the fluid level satisfactory?

--

System OK

--

10

The transmission is contaminated with engine coolant.

Replace the cooler.

Is the replacement complete?

--

Go to Step 12

--

11

Important: Transmission fluid may turn dark with normal use. This does not always indicate oxidation or contamination.

Drain the fluid to determine if the fluid is contaminated.

Refer to Oil Pan Replacement .

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 12

Go to Step 13

12

Overhaul the transmission. Refer to Transmission Overhaul in Transmission Unit Repair Manual.

Is the overhaul complete?

--

Go to Step 13

--

13

Flush the cooler.

Refer to Transmission Fluid Cooler Flushing and Flow Test .

Has the cooler been flushed?

--

Go to Step 14

--

14

Change the fluid and the filter.

Refer to Automatic Transmission Fluid Filter and Seal Replacement .

Is the procedure complete?

--

Go to Step 15

--

15

Add new fluid to the proper level, in the middle of the X-hatch.

Is the procedure complete?

--

System OK

--