DTC P0826 3.5L
Circuit Description
The transmission adaptive pressure (TAP) Shift system allows the driver to manually shift gears by using the TAP Shift switches located on the Automatic Transmission Shifter. Pushing the Up switch will command an upshift and pushing the Down switch will command a downshift. The TAP Shift system is activated when the gear selector is in the D3 position and is deactivated in all other positions.
If the powertrain control module (PCM) detects an invalid voltage on the TAP up/TAP down switch signal circuit, 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 engine speed is greater than 500 RPM for 5 seconds and not in fuel cut off.
Conditions for Setting the DTC
The PCM detects an invalid voltage on the TAP up/TAP down switch signal circuit for 5 seconds.
Action Taken When the DTC Sets
| • | The PCM does not illuminate the malfunction indicator lamp (MIL). |
| • | The PCM commands a alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting. |
| • | The PCM disables TAP Shift operation. |
| • | 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 | |||||||
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 9 | Go to Step 8 | ||||||
5 |
Refer to Circuit Protection - Fuses . Was the fuse open? | -- | Go to Step 6 | Go to Step 7 | ||||||
6 |
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. Refer to Testing for Short to Ground and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Testing for Intermittent Conditions and Poor Connections | ||||||
7 | Test the ignition 1 voltage circuit and the TAP Up/TAP Down switch signal circuit of the Floor Shift Control for an open between the fuse block and the Floor Shift Control. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 8 | ||||||
8 | Test the TAP up/Tap down signal circuit for a short to voltage between the Floor Shift Control and the PCM. Refer to Testing for a Short to Voltage and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 | ||||||
9 |
Is the resistance within the specified range? | 8.11-8.39K ohms | Go to Step 11 | Go to Step 10 | ||||||
10 | Replace the Floor Shift Control. Refer to Transmission Control Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
11 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
12 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 13 | Go to Step 2 | ||||||
13 | 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 |
