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.
If the powertrain control module (PCM) detects an invalid request, then DTC P0826 sets. DTC P0826 is a type C DTC.
This diagnostic procedure supports the following DTC:
DTC P0826 Up and Down Shift Switch Circuit
The ignition is ON.
The PCM detects an invalid TAP Shift request for 1 second.
• | The PCM does not illuminate the malfunction indicator lamp (MIL). |
• | The PCM disables TAP shift operation. |
• | The PCM assumes D4 for shifting. |
• | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records. |
• | The PCM stores DTC P0826 in PCM history. |
• | A scan tool can clear the DTC. |
• | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
• | The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes. |
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear DTC Information function erases the Failure Records from the PCM. Does the scan tool Driver Shift Request parameter display None? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||
3 | Select Driver Shift Request Voltage on the scan tool. Does the Driver Shift Request Voltage parameter display a value higher than specified? | 0.5 V | Go to Step 4 | Go to Step 5 | ||||||
4 | Does the Driver Shift Request Voltage parameter display a value lower than specified? | 4.5 V | Go to Step 10 | Go to Step 9 | ||||||
5 |
Was the fuse open? | -- | Go to Step 6 | Go to Step 7 | ||||||
6 |
Caution: Refer to SIR Caution in the Preface section. Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution. Did you find and correct the condition? | -- | Go to Step 13 | Go to Testing for Intermittent Conditions and Poor Connections | ||||||
7 |
Caution: Refer to SIR Caution in the Preface section. Test the ignition 1 voltage circuit of the left TAP shift switch for an open between the fuse block and the left TAP shift switch. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 | ||||||
8 | Test the remote shift selector signal circuit of the left TAP shift switch for an open or short to ground between the left TAP shift switch and the PCM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||
9 |
Caution: Refer to SIR Caution in the Preface section. Test the remote shift selector signal circuit of the left TAP shift switch for a short to voltage between the left TAP shift switch and the PCM. Refer to Testing for a Short to Voltage and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||
10 |
Did you find a condition? | 8.11-8.39K ohms Static 2.83-2.93K ohms Upshift 1.25-1.29K ohms Downshift | Go to Step 11 | Go to Step 12 | ||||||
11 | Replace the left TAP shift switch. Refer to Automatic Transmission Manual Shift Auxiliary Position Switch Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- | ||||||
12 | Replace the PCM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | -- | Go to Step 13 | -- | ||||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 14 | Go to Step 2 | ||||||
14 | With a scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
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.
If the transmission control module (TCM) detects an invalid request, then DTC P0826 sets. DTC P0826 is a type C DTC.
This diagnostic procedure supports the following DTC:
DTC P0826 Up and Down Shift Switch Circuit
• | DTC P0826 is not active. |
• | The engine speed is greater than 500 RPM for 5 seconds. |
• | The time since the last range change is 6 seconds or greater. |
The TCM detects an invalid TAP shift request for 5 seconds.
• | The TCM does not illuminate the malfunction indicator lamp (MIL). |
• | The TCM disables TAP shift operation. |
• | The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting. |
• | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records. |
• | The TCM stores DTC P0826 in PCM history. |
• | A scan tool can clear the DTC. |
• | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
• | The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes. |
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear DTC Information function erases the Failure Records from the TCM. Does the scan tool Driver Shift Request parameter display None? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||
3 | Select Driver Shift Request Voltage on the scan tool. Does the Driver Shift Request Voltage parameter display a value higher than specified? | 0.5 V | Go to Step 4 | Go to Step 5 | ||||||
4 | Does the Driver Shift Request Voltage parameter display a value lower than specified? | 4.5 V | Go to Step 10 | Go to Step 9 | ||||||
5 |
Was the fuse open? | -- | Go to Step 6 | Go to Step 7 | ||||||
6 |
Caution: Refer to SIR Caution in the Preface section. Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution. Did you find and correct the condition? | -- | Go to Step 13 | Go to Testing for Intermittent Conditions and Poor Connections | ||||||
7 |
Caution: Refer to SIR Caution in the Preface section. Test the ignition 1 voltage circuit of the left TAP shift switch for an open between the fuse block and the left TAP shift switch. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 | ||||||
8 | Test the remote shift selector signal circuit of the left TAP shift switch for an open or short to ground between the left TAP shift switch and the TCM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||
9 |
Caution: Refer to SIR Caution in the Preface section. Test the remote shift selector signal circuit of the left TAP shift switch for a short to voltage between the left TAP shift switch and the TCM. Refer to Testing for a Short to Voltage and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||
10 |
Did you find a condition? | 8.11-8.39K ohms Static 2.83-2.93K ohms Upshift 1.25-1.29K ohms Downshift | Go to Step 11 | Go to Step 12 | ||||||
11 | Replace the left TAP shift switch. Refer to Automatic Transmission Manual Shift Auxiliary Position Switch Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- | ||||||
12 | Replace the TCM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | -- | Go to Step 13 | -- | ||||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 14 | Go to Step 2 | ||||||
14 | With a scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |