DTC P0826 3.8L
Circuit Description
The 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 PCM detects an invalid request, then DTC P0826 sets. DTC P0826 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0826 Up and Down Shift Switch Circuit
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
PCM detects an invalid TAP Shift request for 1 second.
Action Taken When the DTC Sets
| • | 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. |
Conditions for Clearing the DTC
| • | 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 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||
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 Intermittent Conditions in Engine Controls - 3.8L | 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 |
Refer to Circuit Protection - Fuses in Wiring Systems. 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 in Wiring Systems for complete circuit distribution. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Intermittent Conditions in Engine Controls - 3.8L | ||||||
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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Computer/Integrating Systems for replacement, set-up 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? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
DTC P0826 5.3L
Circuit Description
The 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 TCM detects an invalid request, then DTC P0826 sets. DTC P0826 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0826 Up and Down Shift Switch Circuit
Conditions for Running the DTC
| • | 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 more. |
Conditions for Setting the DTC
The TCM detects an invalid TAP shift request for 5 seconds.
Action Taken When the DTC Sets
| • | 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. |
Conditions for Clearing the DTC
| • | 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 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||
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 Intermittent Conditions in Engine Controls - 5.3L | 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 |
Refer to Circuit Protection - Fuses in Wiring Systems. 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 in Wiring Systems for complete circuit distribution. Did you find and correct the condition? | -- | Go to Step 13 | Go to Intermittent Conditions in Engine Controls - 5.3L | ||||||
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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. 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 in Computer/Integrating Systems 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? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
