B1825
DTC B1825, B1850, B2355, B2365, or B2375
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC B1825
- Driver Seat Recline Position Sensor Circuit
DTC B2355
- Driver Seat Front Vertical Position Sensor Circuit
DTC B2365
- Driver Seat Rear Vertical Position Sensor Circuit
DTC B2375
- Driver Seat Horizontal Position Sensor Circuit
Diagnostic Fault Information
Circuit/System Description
The front vertical, rear vertical, horizontal, and recline seat position sensors are potentiometers that are either attached directly to the motor transmission cable or are an internal part of the motor. The memory seat module (MSM) supplies a 5-volt reference voltage through the 5-volt reference circuit and ground through the low reference circuit to the respective seat position sensors. When the motor or cable rotates, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. This voltage varies from 0.25-4.75 volts. The MSM monitors this voltage signal to determine the position of the seat. When the MSM detects that one of the seat position sensor signal circuits is out of the voltage range of 0.25-4.75 volts, a DTC will be set for that signal circuit.
Conditions for Running the DTC
* DTC B1327 must not be present.
* Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B1825
* The DTC will set when the MSM detects a short to voltage, short to ground, or an open/high resistance in the recline seat motor position sensor signal circuit.
* The DTC will set for a short to voltage, short to ground, or an open/high resistance in the seat position sensor 5-volt reference circuit.
* The DTC will set for an open/high resistance in the seat position sensor low reference circuit.
B2355
* The DTC will set when the MSM detects a short to voltage, short to ground, or an open/high resistance in the front vertical seat motor position sensor signal circuit.
* The DTC will set for a short to voltage, short to ground, or an open/high resistance in the seat position sensor 5-volt reference circuit.
* The DTC will set for an open/high resistance in the seat position sensor low reference circuit.
B2365
* The DTC will set when the MSM detects a short to voltage, short to ground, or an open/high resistance in the rear vertical seat motor position sensor signal circuit.
* The DTC will set for a short to voltage, short to ground, or an open/high resistance in the seat position sensor 5-volt reference circuit.
* The DTC will set for an open/high resistance in the seat position sensor low reference circuit.
B2375
* The DTC will set when the MSM detects a short to voltage, short to ground, or an open/high resistance in the horizontal seat motor position sensor signal circuit.
* The DTC will set for a short to voltage, short to ground, or an open/high resistance in the seat position sensor 5-volt reference circuit.
* The DTC will set for an open/high resistance in the seat position sensor low reference circuit.
Actions Taken When the DTC Sets
The motor associated with the fault will be disabled for memory functions.
Conditions for Clearing the DTCs
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
The memory seat module (MSM) is also referred to as the driver position module (DPM) in certain scan tool menus.
Reference Information
Schematic Reference
Driver Seat Schematics (Driver Seat Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Memory Seats Description and Operation (Memory Seats Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)
Circuit/System Testing
1. Ignition OFF, disconnect the X2 harness connector at the driver seat adjuster motor assembly.
2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
3. Ignition OFF, disconnect the X3 harness connector at the driver seat adjuster motor assembly.
4. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
5. Ignition OFF, disconnect the X4 harness connector at the driver seat adjuster motor assembly.
6. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal C and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
7. Ignition OFF, disconnect the X2 harness connector at the driver seat recline motor assembly.
8. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal D and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
9. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C at the driver seat adjuster motor X2 harness connector and ground.
• If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance.
• If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
10. Test for 4.8-5.2 volts between the 5-volt reference circuit terminal C at the X3 harness connector and ground.
• If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance.
• If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
11. Test for 4.8-5.2 volts between the 5-volt reference circuit terminal A at the X4 harness connector and ground.
• If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
• If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
12. Test for 4.8-5.2 volts between the 5-volt reference circuit terminal A at the driver seat recline X2 harness connector and ground.
• If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
• If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
13. Verify with a scan tool that each driver seat sensor parameter is less than 2 volts.
• If greater than 2 volts, test the appropriate sensor signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
14. Install a 3A fused jumper wire between the appropriate sensor signal circuit and the sensor 5-volt reference circuit. Verify with a scan tool the appropriate seat sensor parameter is greater than 4.75 volts.
• If less than 4.75 volts, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
15. If all circuits test normal, test or replace the appropriate seat motor assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver Seat Adjuster and Recliner Switch Replacement (Driver Seat Adjuster and Recliner Switch Replacement)
* Driver Seat Adjuster Replacement (Driver Seat Adjuster Replacement)
* Control Module References (Programming and Relearning) for MSM replacement, setup, and programming