GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Gears are changed by the following methods:

    • The transmission control module (TCM) controlling solenoid vales A and B
    • The select lever operating the manual valve

When the select lever is in the P, N or R position, the manual valve and line pressure operates the gear change mechanically.

In the other positions, shifting up and down to 1st, 2nd, 3rd, and 4th gears is controlled by shift solenoid valves A and B.

If the automatic transmission fluid temperature is less than 20°C (68°F), shifting up to 4th gear is not possible.

Conditions for Running the DTC

    • Automatic transmission oil temperature is between 0°C (32°F) and 120°C (248°F).
    • The fault is immediately recognized with ignition ON.
    • The fault is immediately recognized after the engine starts.

Conditions for Setting the DTC

The shift circuit has an open or short to voltage.

Action Taken When the DTC Sets

    • The TCM illuminates the A/T warning lamp when the diagnostic runs and fails.
    • The converter clutch remains disengaged at all times.

Conditions for Clearing the MIL/DTC

The TCM turns OFF the A/T warning lamp when the diagnostic runs and does not fail.

DTC 53

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2

  1. Ignition OFF.
  2. Disconnect TCM connector.
  3. Using a DMM, measure resistance between TCM connector terminal 21 and ground.

Is the resistance within the specified value?

11-14 ohms

Go to Step 3

Go to Step 5

3

  1. Disconnect the shift solenoid connector.
  2. Using a DMM, measure resistance between the shift solenoid connector terminal B1 and the TCM connector terminal 21.

Is the resistance greater than the specified value?

0.3 ohms

Go to Step 6

Go to Step 4

4

Using a DMM, measure voltage between the shift solenoid connector terminal B1 and ground.

Is the voltage greater than the specified value?

0V

Go to Step 7

Go to Step 8

5

Replace the shift solenoid A.

Did you complete the replacement?

--

Go to Step 9

--

6

Repair an open in the shift solenoid A circuit.

Did you complete the repair.

--

Go to Step 9

--

7

Repair a short to voltage in the shift solenoid A circuit.

Did you complete the repair?

--

Go to Step 9

--

8

Replace the TCM. Refer to Transmission Control Module Replacement .

Did you complete the repair?

--

Go to Step 9

--

9

  1. Clear the DTCs. Refer to Clearing Transmission Diagnostic Trouble Codes .
  2. Start the engine.
  3. Operate the vehicle within Conditions for Running the DTC.

Does the DTC reset?

--

Go to Step 2

System OK