DTC 22. Chevrolet Joy 2008

For 1990-2009 cars

### Circuit Description

Vehicle speed information is provided to the transmission control module (TCM) by the vehicle speed sensor (VSS). The VSS is a permanent magnet generator hat is mounted in the transaxle and produce a pulsing voltage whenever vehicle speed is over 5 km/h (3 mph). The A/C voltage level and the number of pulses increase with vehicle speed. The TCM converts the pulsing voltage into km/h (mph) and than supplies the necessary signal to the instrument cluster for speedometer and/or odometer operation and to the cruise control module and multi-function alarm module operation.

The diagnostic trouble code (DTC) will set if there is no input signal.

### Conditions for Running the DTC

• | System voltage is between 9.0-18.0 volts.

• | Road test the vehicle. Refer to Road Test

### Conditions for Setting the DTC

Engine speed is greater than 600 RPM.

### Action Taken When the DTC Sets

• | The TCM illuminates the A/T warning lamp when the diagnostic runs and fails

• | The transmission will default to third gear only.

• | Line pressure control is set to full throttle.

### Conditions for Clearing the MIL/DTC

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

#### DTC 22

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. Disconnect the VSS.
2. Turn the ignition ON.
3. Using a DMM connected to ground, measure voltage at the VSS harness connector terminal D3.

Is the voltage with the specified value?

11-14 volts

Go to Step 3

Go to Step 5

3

1. Turn the ignition OFF.
2. Connect the VSS connector.
3. Disconnect the TCM connector.
4. Raise and support the vehicle.

Notice: Support the lower control arms in the normal horizontal position in order to avoid damage to the drive axles. Do not operate the vehicle in gear with the wheels hanging down at full travel.

5. Using a DMM connected to ground, measure the voltage in the vehicle speed sensor (VSS) signal circuit, at the TCM terminal 32 while rotting the wheels.

Is the voltage greater than or equal to specified value?

0.5 volts

Go to Step 12

Go to Step 4

4 | Measure the resistance in the VSS signal circuit. Is the resistance greater than the specified value? | 1950ohms | Go to Step 6 | Go to Step 7
5 | Repair an open in the VSS ignition circuit. Did you complete the repair? | -- | Go to Step 12 | --
6 | Repair an open in the VSS signal circuit. Did you complete the repair? | -- | Go to Step 12 | --
7 | Is the resistance value within the specified value? | 1,300-1,950ohms | Go to Step 8 | Go to Step 9
8 | Inspect the VSS signal circuit for a short to ground or for being shorted together and repair as necessary. Did you complete the repair? | -- | Go to Step 12 | --

9

1. Remove the VSS.
2. Measure the resistance between terminals D1 and D2.

Is the resistance value within the specified value?

1,300-1,950ohms

Go to Step 11

Go to Step 10

10 | Replace the VSS. Did you complete the repair? | -- | Go to Step 12 | --
11 | Replace the TCM. Did you complete the repair? | -- | Go to Step 12 | --

12

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

Does the DTC reset?

--

Go to Step 2

System OK