The 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 Low position and is deactivated in all other positions.
If the powertrain control module (PCM) detects TAP enable switch Inactive and the TR switch indicates D3, DTC P1877 sets. DTC P1877 is a type C DTC.
This diagnostic procedure supports the following DTC:
DTC P1877 Up and Down Shift Switch Performance - Range Switch in D3
• | No TAP system DTCs P0815, P0816 or P0826. |
• | No PSA DTCs P1810, P1816, or P1818. |
• | No TAP system performance DTC 1876. |
• | The engine run time is greater than 5 seconds. |
The PCM detects the TAP enable switch is Inactive and the TR switch indicates D3 for 3 seconds.
• | The PCM does not illuminate the malfunction indicator lamp (MIL). |
• | The PCM disables TAP Shift operation. |
• | The PCM assumes a D4 shift pattern. |
• | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information a Failure Record. |
• | The PCM stores DTC P1877 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. |
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 Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 | ||||||
3 |
Refer to Circuit Protection - Fuses in Wiring Systems. Was the fuse open? | -- | Go to Step 4 | Go to Step 5 | ||||||
4 |
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 10 | Go to Intermittent Conditions in Engine Controls - 2.2L or Intermittent Conditions in Engine Controls - 3.5L | ||||||
5 | Test the ignition 1 voltage circuit of the A/T Shift Program Switch for an open between the fuse block and the A/T Shift Program Switch. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 | ||||||
6 | Test the signal circuit of the A/T Shift Program Switch for an open or short to ground between the A/T Shift Program Switch and the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 | ||||||
7 |
Is the resistance within the specified range? | 8.11-8.39K ohms | Go to Step 9 | Go to Step 8 | ||||||
8 | Replace the A/T Shift Program Switch. Refer to Transmission Control Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||
9 | 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 10 | -- | ||||||
10 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 11 | Go to Step 2 | ||||||
11 | 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 |