DTC P0815, P0816, or P0826
|
|
DTC P0815, P0816, or P0826
|
DTC P0815
Upshift Switch Circuit
DTC P0816
Downshift Switch Circuit
DTC P0826
Up and Down Shift Switch Circuit
|
Diagnostic Fault Information
|
Driver Shift Request
|
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
|
Tap Upshift Switch
|
P0826
|
P0826
|
P0815
|
-
|
|
Tap Downshift Switch
|
P0826
|
P0826
|
P0816
|
-
|
|
Up and Down Shift Switch
|
P0826
|
P0826
|
P0826
|
-
|
Driver Shift Request
|
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
|
Tap Up/Tap Down Switch Signal
|
Invalid
|
None
|
Invalid/None
|
|
Circuit/System Description
|
When the shift lever is placed in manual mode (M), this activates the driver shift request (DSR), also known as the tap shift function. The DSR allows the vehicle operator to shift gears by pushing the shift lever forward for an upshift or pulling the shift lever rearward for a downshift. The body control module (BCM) supplies battery voltage, ground and a signal circuit to the shift controller. The shift controller has Hall-effect switches connected to a resistor array. When the lever is in the M position, then pushed forward for an upshift, or pulled rearward for a downshift, a corresponding voltage drop occurs across the resistor network. This voltage drop is monitored by the BCM. The BCM will send the request to the transmission control module (TCM) to perform the upshift or downshift.
|
Conditions for Running the DTC
|
P0815 or P0816
|
•
|
DTC P0815, P0816, P0826, P1761, P182E, P1876, P1877, or P1915 is not set.
|
|
•
|
The time since the range change is 1 second or greater.
|
|
•
|
The engine speed is 400 RPM or greater for 5 seconds.
|
|
•
|
The ignition voltage is 8.6 volts or greater.
|
P0826
|
•
|
The engine speed is 400 RPM or greater for 5 seconds.
|
|
•
|
The ignition voltage is 8.6 volts or greater.
|
|
•
|
DTC P0826 or P1761 is not set.
|
|
Conditions for Setting the DTC
|
P0815 - Condition 1
The TCM detects an upshift request for 1 second in PARK or neutral.
P0815 - Condition 2
The TCM detects an upshift request for 10 minutes in any forward range.
P0816 - Condition 1
The TCM detects a downshift request for 1 second in PARK or neutral.
P0816 - Condition 2
The TCM detects a downshift request for 10 minutes in any forward range.
P0826
The TCM detects an invalid voltage on the Tap up/Tap down signal circuit for 1 minute.
|
Action Taken When the DTC Sets
|
|
•
|
DTCs P0815, P0816, and P0826 are Type C DTCs.
|
|
•
|
The TCM inhibits Tap Up/Down function.
|
|
•
|
The TCM inhibits manual shifting of forward gears.
|
|
Conditions for Clearing the DTC
|
DTCs P0815, P0816, and P0826 are Type C DTCs.
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Description and Operation
Transmission General Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
|
Circuit/System Verification
|
|
1.
|
Ignition ON, observe the scan tool Driver Shift Control parameter, while moving the transmission shift lever through the park, reverse, neutral, and drive positions. The reading should display Inactive.
|
|
2.
|
Shift lever in the M position, observe the scan tool Driver Shift Request parameter while pushing the shift lever forward and pulling the shift lever rearward. The parameter should change from None to Upshift or Downshift.
|
|
3.
|
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
|
|
1.
|
Ignition OFF, disconnect the shift lever assembly electrical connector from the shift lever assembly.
|
|
2.
|
Test for less than 10 ohms between the shift lever harness connector terminal 2 and ground.
|
|
3.
|
If greater than the specified range, repair the ground circuit.
|
|
4.
|
Ignition ON, verify the scan tool Driver Shift Control parameter displays inactive.
|
|
5.
|
If not the expected results, test the signal circuit between shift lever assembly connector terminal 3 and the BCM for a short to voltage or ground. If the circuit tests normal, replace the BCM.
|
|
6.
|
Ignition OFF, connect a test lamp between shift lever harness connector B+ terminal 1 and ground circuit terminal 2.
|
|
7.
|
Ignition ON, verify the test lamp is illuminated.
|
|
8.
|
If the light stays off, test the B+ circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
|
|
9.
|
Test for 11-13 volts at the shift lever assembly harness connector between signal circuit terminal 3 and ground.
|
|
10.
|
If not within the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
|
|
11.
|
Ignition OFF, connect the shift lever harness connector.
|
|
12.
|
Ignition ON, back probe the shift lever assembly connector and test for 11-13 volts between terminal 3 and ground with the shift lever in park, reverse, neutral, and drive.
|
|
13.
|
If not within the specified range, replace the shift lever assembly.
|
|
14.
|
Use a DMM to monitor the voltage between the shift lever assembly's connection terminal 3 and ground with the gear select lever in M, button up and button down position. Compare the readings and verify the voltages are correct for each position as follows:
|
|
|
•
|
Tap down: 5.1-7.3 volts
|
|
15.
|
If not within the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the shift lever assembly.
|
|
16.
|
If all circuits test normal, replace the BCM.
|
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
