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For 1990-2009 cars only

TAP Shift Circuit Performance 3.8L


Object Number: 1440601  Size: LF
Master Electrical Component List
Automatic Transmission Controls Schematics (LS4)
Automatic Transmission Controls Schematics (L26, L32)
OBD II Symbol Description Notice
Control Module References

Circuit Description

The touch activated power (TAP) shift system allows the driver to manually shift gears by using the TAP shift switches located on the steering wheel. Pushing either TAP shift switch will command an upshift and pulling the switch will command a downshift. The TAP shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic Systems Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select The DTC Info parameter on the scan tool.

Is DTC P0815, P0816 or P0826 set?

--

Go to Diagnostic Trouble Code (DTC) List/Type

Go to Step 3

3

  1. Select the Driver Shift Request parameter on the scan tool.
  2. Operate the left TAP shift switch in the upshift and downshift positions.

Does the scan tool Driver Shift Request parameter display upshift in the upshift position and downshift in the downshift position?

--

Go to Step 4

Go to Step 13

4

Operate the right TAP shift switch in the upshift and downshift positions.

Does the scan tool Driver Shift Request parameter display upshift in the upshift position and downshift in the downshift position?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 5

5

Does the Driver Shift Request parameter display upshift in the upshift position?

--

Go to Step 7

Go to Step 6

6

Does the Driver Shift Request parameter display downshift in the downshift position?

--

Go to Step 9

Go to Step 11

7

Caution: Refer to SIR Caution in the Preface section.

Using the DMM and the J 35616 GM terminal test kit, measure the resistance between the downshift request circuit and the remote shift selector signal circuit of the left TAP shift switch. Refer to Testing for Continuity .

Does the resistance measure within the specified range?

1.47-1.53K ohms

Go to Step 8

Go to Step 13

8

Test the downshift request circuit for an open between the left and right TAP switches. Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

9

Caution: Refer to SIR Caution in the Preface section.

Using the DMM and the J 35616 , measure the resistance between the upshift request circuit and the remote shift selector signal circuits of the left TAP shift switch. Refer to Testing for Continuity .

Does the resistance measure within the specified range?

4.34-4.50K ohms

Go to Step 10

Go to Step 13

10

Test the upshift request circuit for an open between the left and right TAP switches. Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

11

Caution: Refer to SIR Caution in the Preface section.

Using the DMM and the J 35616 , measure the resistance between the ignition 1 voltage circuit and the right TAP shift switch supply voltage circuit of the left TAP shift switch. Refer to Testing for Continuity .

Does the resistance measure greater than the specified value?

10 ohms

Go to Step 13

Go to Step 12

12

Test the ignition 1 voltage circuit for an open between the left and right TAP switches. Refer to Testing for Continuity .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Replace the left TAP shift switch. Refer to Automatic Transmission Manual Shift Auxiliary Position Switch Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

Replace the right TAP shift switch. Refer to Automatic Transmission Manual Shift Auxiliary Position Switch Replacement .

Did you complete the replacement?

--

Go to Step 15

--

15

Perform the following procedure in order to verify the repair:

  1. Select the Driver Shift Request parameter on the scan tool.
  2. Operate the left and right TAP shift switches in the upshift and downshift positions.

Does the scan tool Driver Shift Request parameter display upshift in the upshift position and downshift in the downshift position for both TAP shift switches?

--

System OK

Go to Step 1

TAP Shift Circuit Performance 5.3L


Object Number: 1582620  Size: LF
Master Electrical Component List
Automatic Transmission Controls Schematics (LS4)
Automatic Transmission Controls Schematics (L26, L32)
OBD II Symbol Description Notice
Control Module References

Circuit Description

The touch activated power (TAP) shift system allows the driver to manually shift gears by using the TAP shift switches located on the steering wheel. Pushing either TAP shift switch will command an upshift and pulling the switch will command a downshift. The TAP shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic Systems Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select The DTC Info parameter on the scan tool.

Is DTC P0815, P0816 or P0826 set?

--

Go to Diagnostic Trouble Code (DTC) List/Type

Go to Step 3

3

  1. Select the Driver Shift Request parameter on the scan tool.
  2. Operate the left TAP shift switch in the upshift and downshift positions.

Does the scan tool Driver Shift Request parameter display upshift in the upshift position and downshift in the downshift position?

--

Go to Step 4

Go to Step 13

4

Operate the right TAP shift switch in the upshift and downshift positions.

Does the scan tool Driver Shift Request parameter display upshift in the upshift position and downshift in the downshift position?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 5

5

Does the Driver Shift Request parameter display upshift in the upshift position?

--

Go to Step 7

Go to Step 6

6

Does the Driver Shift Request parameter display downshift in the downshift position?

--

Go to Step 9

Go to Step 11

7

Caution: Refer to SIR Caution in the Preface section.

Using the DMM and the J 35616 GM terminal test kit, measure the resistance between the downshift request circuit and the remote shift selector signal circuit of the left TAP shift switch. Refer to Testing for Continuity .

Does the resistance measure within the specified range?

1.47-1.53K ohms

Go to Step 8

Go to Step 13

8

Test the downshift request circuit for an open between the left and right TAP switches. Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

9

Caution: Refer to SIR Caution in the Preface section.

Using the DMM and the J 35616 , measure the resistance between the upshift request circuit and the remote shift selector signal circuits of the left TAP shift switch. Refer to Testing for Continuity .

Does the resistance measure within the specified range?

4.34-4.50K ohms

Go to Step 10

Go to Step 13

10

Test the upshift request circuit for an open between the left and right TAP switches. Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

11

Caution: Refer to SIR Caution in the Preface section.

Using the DMM and the J 35616 , measure the resistance between the ignition 1 voltage circuit and the right TAP shift switch supply voltage circuit of the left TAP shift switch. Refer to Testing for Continuity .

Does the resistance measure greater than the specified value?

10 ohms

Go to Step 13

Go to Step 12

12

Test the Ignition 1 voltage circuit for an open between the left and right TAP switches. Refer to Testing for Continuity and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Replace the left TAP shift switch. Refer to Automatic Transmission Manual Shift Auxiliary Position Switch Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

Replace the right TAP shift switch. Refer to Automatic Transmission Manual Shift Auxiliary Position Switch Replacement .

Did you complete the replacement?

--

Go to Step 15

--

15

Perform the following procedure in order to verify the repair:

  1. Select the Driver Shift Request parameter on the scan tool.
  2. Operate the left and right TAP shift switches in the upshift and downshift positions.

Does the scan tool Driver Shift Request parameter display upshift in the upshift position and downshift in the downshift position for both TAP shift switches?

--

System OK

Go to Step 1