Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B1395 02: Device Voltage Reference Output Circuit Short to GroundDTC B1395 05: Device Voltage Reference Output Circuit Short to Battery or Open
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference | B1395 02, B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06, B2105 06, B2860 06, B2880 06 | B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06, B2105 06, B2860 06, B2880 06 | B1395 05, B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01, B2105 01, B2860 01, B2880 01 | B1825 5A, B1850 5A, B1860 5A, B2355 5A, B2365 5A, B2375 5A, B2860 5A, B2880 5A |
Driver Seat Front Vertical Position Sensor Signal | B2355 06 | B2355 06 | B2355 01 | -- |
Driver Seat Rear Vertical Position Sensor Signal | B2365 06 | B2365 06 | B2365 01 | -- |
Driver Seat Horizontal Position Sensor Signal | B2375 06 | B2375 06 | B2375 01 | -- |
Driver Seat Lumbar Vertical Position Sensor Signal | B1860 06 | B1860 06 | B1860 01 | -- |
Driver Seat Lumbar Horizontal Position Sensor Signal | B1850 06 | B1850 06 | B1850 01 | -- |
Driver Seat Recline Position Sensor Signal | B1825 06 | B1825 06 | B1825 01 | -- |
Passenger Seat Lumbar Vertical Position Sensor Signal | B2105 06 | B2105 06 | B2105 01 | -- |
Memory Seat/Mirror Sensor Low Reference | -- | B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01, B2105 01, B2860 01, B2880 01 | -- | B1825 5A, B1850 5A, B1860 5A, B2355 5A, B2365 5A, B2375 5A, B2860 5A, B2880 5A |
Circuit/System Description
The memory seat module (MSM) supplies a 5-volt reference voltage to the driver seat position sensors, lumbar position sensors, passenger seat lumbar vertical position sensor, and the steering column position sensors. The MSM monitors this reference voltage to ensure the accuracy of the voltages being returned from the sensors. If the voltage exceeds the normal operating range, errors will occur in the memory recall operations of the seat and steering column.
Conditions for Running the DTC
The MSM must be powered.
Conditions for Setting the DTC
B1395 02
The reference voltage drops below 4.8 volts for more than 300 mS.
B1395 05
The reference voltage exceeds 5.2 volts for more than 300 mS.
Action Taken When the DTC Sets
All memory recall and seat massage functions will be disabled.
Conditions for Clearing the DTC
| • | The current DTC will clear and set the code to history 3 seconds after the reference voltage returns to normal operating range and the power mode changes to OFF then back to ACC or RUN. |
| • | The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred. |
Diagnostic Aids
| • | The scan tool may reference the Memory Seat Module (MSM) as the Driver Position Module. |
| • | All seat, lumbar, and tilt/telescoping steering column position sensors use common ground and 5-volt reference circuits. |
| • | If the 5-volt reference circuit is shorted to voltage multiple position sensor codes will set. |
| • | If the 5-volt reference circuit is shorted to ground multiple position sensor codes will set. |
| • | A short to voltage on one of the position sensor signal circuits may set this code. |
| • | An internal short to ground in one of the position sensors may set this code. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Memory Seats Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector for all position sensors connected to the 5-volt reference circuit.
- Ignition ON, observe all scan tool sensor parameters for Seat 1 Info, Seat 2 Info, and Column Info. The readings should be 0.0 volts.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit at any one of the position sensors and ground.
- Connect each position sensor one at a time and verify that the DTC does not set as current.
- If all circuits test normal, replace the MSM.
| ⇒ | If greater than the specified value, test the appropriate signal circuits listed below for a short to voltage. If the circuit tests normal, replace the MSM. |
| • | Driver seat horizontal position sensor terminal 3 X2 |
| • | Driver seat front vertical position sensor terminal 1 X2 |
| • | Driver seat rear vertical position sensor terminal 5 X2 |
| • | Driver seat recline position sensor terminal 2 X2 |
| • | Driver seat lumbar horizontal position sensor terminal 2 |
| • | Driver seat lumbar vertical position sensor terminal 2 |
| • | Passenger seat lumbar vertical position sensor terminal B X353 |
| • | Tilt position sensor terminal C X2 |
| • | Telescope position sensor terminal C X2 |
| ⇒ | If less than the specified range, 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 the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM. |
| ⇒ | If the DTC sets as current, replace the appropriate position sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for MSM replacement, setup, and programming |
