GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

    Important: Ensure that the transmission fluid is at the specified value.

  1. Install a scan tool and observe the transmission fluid temperature.
  2. Start the vehicle, and with the engine idling, depress the brake pedal and move the shift lever through the gear ranges, pausing a few seconds in each range. Return the shift lever to the PARK range.
  3. Raise the vehicle on a hoist. The vehicle must be level with the engine running and the shift lever in the PARK range. Refer to Lifting and Jacking the Vehicle in General Information.
  4. Support the transmission with a suitable jack.
  5. Important: The transmission must be in the vehicle operating position to accurately check fluid level.

  6. Remove the bolts securing the transmission crossmember to the vehicle and the transmission. Slide the crossmember as far rearward as possible.
  7. Caution: Refer to Checking Hot Transmission Fluid through Drain Plug Hole Caution in the Preface section.

    Important: Some transmission fluid loss may occur when the fluid level hole plug is removed.

  8. Remove the transmission fluid level hole plug (36).
  9. Important: The transmission fluid may darken with normal use and does not always indicate contamination or oxidation.

  10. Inspect the fluid color.

Is the fluid color red or light brown with no burnt odor?

30-50°C (86-122°F)

Go to Step 4

Go to Step 2

2

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

--

Go to Step 8

Go to Step 3

3

Does the fluid have a cloudy or milky appearance?

--

Go to Step 7

Go to Step 8

4

Let the fluid temperature rise until it has reached the specified value. Inspect the fluid level. The level should be even with the bottom of the threaded plug hole.

Is the fluid level low?

30-50°C (86-122°F)

Go to Step 5

Go to Step 11

5

Add DEXRON® III automatic transmission fluid in increments of 0.5 L (0.5 qt) until the fluid drains from the hole plug.

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

--

Go to Step 6

Go to Step 11

6

The transmission may have a leak. Refer to Fluid Leak Diagnosis .

Was a transmission leak found?

--

Go to Step 9

Go to Step 11

7

The transmission fluid is contaminated with engine coolant.

Repair or replace the transmission cooler in the radiator.

Is the transmission cooler repair complete?

--

Go to Step 9

--

8

  1. Drain the fluid by removing the transmission fluid pan drain plug (63) if equipped.
  2. Remove the transmission fluid pan. Refer to Automatic Transmission Fluid and Filter Replacement .
  3. Important: A very small amount of material in the bottom of the pan is a normal condition.

  4. Inspect the bottom pan for any excessive debris.

Was excessive debris found?

--

Go to Step 9

Go to Step 10

9

  1. Repair the transmission, if required.
  2. Important: If the transmission is overhauled, it may be necessary to flush the transmission fluid cooler and pipes. Refer to Transmission Fluid Cooler Flushing and Flow Test .

  3. Perform the transmission fluid checking procedure starting with step 1.

Is the repair complete?

--

System OK

--

10

  1. Change the fluid and fluid filter. Refer to Automatic Transmission Fluid and Filter Replacement .
  2. Perform the transmission fluid checking procedure starting with step 1.

Is the repair complete?

--

System OK

--

11

    Notice: Refer to Fastener Notice in the Preface section.

    Important: If the level hole plug (36) and O-ring (37) are not damaged, they should be reused.

  1. Let the AT fluid temperature rise until it has reached the specified value. Allow fluid to finish draining out of the hole plug. Inspect the level hole plug (36) and O-ring (37) for damage. Install the transmission level hole plug (36) and tighten to the specified value.
  2. Wipe any excess fluid from the transmission with a shop towel or rag.
  3. Install the crossmember.
  4. Remove transmission jack.
  5. Lower the vehicle.

Is the repair complete?

30-50°C (86-122°F)

20 N·m (15 lb ft)

System OK

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