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.
Conditions for Running the DTC
| • | The system voltage is 8-18 volts. |
| • | 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 - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 3.8L | ||||||
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: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling . Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs. 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: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling . Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs. 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: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling . Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs. 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 Powertrain Control Module Replacement in Engine Controls - 3.8L. 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 in Engine Controls - 3.8L | System OK |
