P1876
DTC P1876
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P1876
- Up and Down Shift Enable Switch Circuit Low Voltage
Circuit/System Description
When the shift lever is moved left of the D position, the transmission will enter sport mode. With the shift lever in this position, the transmission will enter manual mode if the gear shift lever is pressed forward or rearward. This allows the operator to select an upshift by pressing the gear shift lever forward, and downshift by pressing the gear shift lever rearward. The body control module (BCM) supplies a signal circuit to the shift controller. The shift controller has Hall-effect switches connected to a resistor array. When the lever is left of the D position, a voltage drop occurs across the resistor network. When the gear shift lever is pressed forward or rearward, 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 to perform the upshift or downshift.
Conditions for Running the DTC
* DTC P0815, P0816, or P0826, P1825, P1915 or U0100 is not set.
* Engine speed is 400 RPM or greater for 5 seconds.
* Ignition voltage is 8.6 V or greater.
Conditions for Setting the DTC
The Tap Up/Tap Down switch signal is Active when the IMS does not indicate L (M) for 2 seconds or greater 3 times during the same ignition cycle.
Action Taken When the DTC Sets
* DTC P1876 is a Type C DTC.
* TCM disables Tap shift functions.
Conditions for Clearing the DIC/DTC
DTC P1876 is a Type C DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
* Transmission General Description Transmission General Description
* Electronic Component Description Electronic Component Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
Warning: Refer to Parking Brake and Drive Wheels Warning Parking Brake and Drive Wheels Warning.
1. Ignition ON.
2. Verify with a scan tool there are no transmission internal mode switch (IMS) DTCs set.
• If IMS DTCs were set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If no IMS DTCs were set
3. Verify the gear shift lever position matches the scan tool TCM Internal Mode Switch parameter while slowly moving the gear shift lever from Park through all ranges.
• If the displayed values are not correct
Refer to Range Selector Lever Cable Adjustment Adjustments.
• If the displayed values are correct
4. Verify the scan tool Driver Shift Control Mode parameter displays Inactive with the transmission shift lever in Park, Reverse, Neutral, and Drive, and Active with the shift lever left of the D or manual mode position.
• If the Driver Shift Mode parameter does not display the correct values
Refer to Circuit/System Testing below.
• If the Driver Shift Mode parameter displays the correct values
5. Shift lever left of the D position.
6. Verify the scan tool Up and Down Shift Switch parameter changes from None to Upshift when the tap up button is pressed, and from None to Downshift when the tap down button is pressed.
• If parameter values are not correct
Refer to Circuit/System Testing below.
• If parameter values are correct
7. After performing the above steps, verify that the DTC does not reset by operating the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions you observe from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure, then STOP. Do not perform the Circuit/System Testing or Component Testing as this may result in an unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections.
Circuit/System Testing
Note: You must perform Circuit/System Verification first.
1. Ignition OFF, disconnect the harness connector from the S3 transmission shift lever. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the S3 transmission shift lever harness connector terminal 2 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test the ground circuit for less than 2 ohms end to end.
• If greater than 2 ohms, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify the scan tool Driver Shift Control parameter displays inactive.
• If Driver Shift Control Parameter does not display Inactive
1. Ignition OFF, disconnect the harness connector at the K9 body control module.
2. Test for infinite resistance between the transmission shift lever vehicle harness connector signal circuit terminal 3 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 body control module.
• If Driver Shift Control Parameter displays Inactive
5. Verify a test lamp illuminates between the S3 transmission shift lever harness connector ignition circuit terminal 1 and ground circuit terminal 2.
• If the test lamp does not illuminate
1. Ignition OFF.
2. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the ignition circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp illuminates
6. Test for 11 V or greater at the S3 transmission shift lever harness connector between signal circuit terminal 3 and ground.
• If less than 11 V
1. Ignition OFF, disconnect the connector at the K9 body control module.
2. Test for less than 2 ohms in the signal circuit wire end to end.
• If 2 ohms or greater, repair the open/high resistance in the signal circuit wire.
• If less than 2 ohms, replace the K9 body control module.
• If 11 V or greater
7. Ignition OFF, connect the S3 transmission shift lever harness connector, ignition ON.
8. Test for 11 V or greater between the S3 transmission shift lever connector terminal 3 and ground in the park, reverse, neutral, and drive gear select lever positions by back probing the connector.
• If less than 11 V
Replace the S3 transmission shift lever.
• If 11 V or greater
9. Shift selector lever left of the D position.
10. Test for 8.0-10.6 V between the S3 transmission shift lever connector terminal 3 and ground.
• If not between 8.0-10.6 V
1. Ignition OFF.
2. Test the signal circuit for less than 2 ohms end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the S3 shift lever.
• If between 8.0-10.6 V
11. Test for 5.1-7.3 V between the S3 transmission shift lever connector terminal 3 and ground with the shift lever pressed forward.
• If not between 5.1-7.3 V
1. Ignition OFF.
2. Test the signal circuit for less than 2 ohms end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the S3 shift lever.
• If between 5.1-7.3 V
12. Test for 2.0-4.6 V between the S3 transmission shift lever connector terminal 3 and ground with the shift lever pressed rearward.
• If not between 2.0-4.6 V
1. Ignition OFF.
2. Test the signal circuit for less than 2 ohms end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the S3 shift lever.
• If between 2.0-4.6 V
13. Replace the K9 body control module.
Repair Instructions
Note:
* Perform the Reset Transmission Adapts Reset Transmission Adapts following all transmission related repairs.
* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Transmission Control Replacement Transmission Control Replacement for AT TAP shift switch replacement
* Control Module References Control Module References for body control module (BCM) or control solenoid valve assembly replacement, setup, and programming