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 valves A and B
    • The select lever operating the manuals 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.

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

Gears are changed by the following methods:

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

DTC 58

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 20 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 B2 and the TCM connector terminal 20.

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 B2 and the TCM connector terminal 20.

--

Go to Step 7

Go to Step 8

5

Replace the shift solenoid B.

Did you complete the replacement?

--

Go to Step 9

--

6

Repair an open in the shift solenoid B circuit.

Did you complete the repair?

--

Go to Step 9

--

7

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

Did you complete the repair?

--

Go to Step 9

--

8

Replace the TCM. Refer to Transmission Control Module Replacement .

Did you complete the replacement?

--

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