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 B1826: Driver Recline Sensor PerformanceDTC B2356: Driver Front Vertical Sensor Performance
DTC B2366: Driver Rear Vertical Sensor Performance
DTC B2376: Driver Seat Assembly Horizontal Sensor Performance
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference - Seat Position Sensors | B1825, B2355, B2365, B2375 | B1825, B2355, B2365, B2375 | B1825, B2355, B2365, B2375 | B1826, B2356, B2366, B2376 |
Front Vertical Position Sensor Signal | B2355 | B2355 | B2355 | -- |
Horizontal Position Sensor Signal | B2375 | B2375 | B2375 | -- |
Recline Position Sensor Signal | B1825 | B1825 | B1825 | -- |
Rear Vertical Position Sensor Signal | B2365 | B2365 | B2365 | -- |
Memory Seat/Mirror Sensor Low Reference | -- | B1825, B2355, B2365, B2375 | -- | B1826, B2356, B2366, B2376 |
Circuit/System Description
The position sensor that sets this diagnostic trouble code (DTC) is either attached to the seat directional motor drive cable or directly to the motor it monitors. It receives a 5-volt reference and low reference from the memory seat module (MSM). The sensor sends a voltage signal that varies with the movement of the seat through the signal circuit to the MSM. Then based on this voltage signal, the MSM determines the position of the seat.
Conditions for Running the DTC
| • | DTC B1327 must not be present. |
| • | Battery voltage must be between 9-16 volts. |
Conditions for Setting the DTC
This DTC will set, if the MSM is controlling a motor in one direction and it's position sensor is tracking the motor in the opposite direction. The sensor is either mounted or wired incorrectly, or the polarity of the motor control circuits are reversed.
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 is also referred to as the Driver Position Module in certain scan tool menus.
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
B1826
- Ignition OFF, disconnect the X1 harness connector at the driver seat recline motor.
- Verify that the control circuits listed below are in the correct harness connector cavities:
- Disconnect the X2 harness connector at the driver seat recline motor.
- Verify that the 5-volt reference and low reference circuits listed below are in the correct harness connector cavities:
- If all circuits test normal, replace the MSM.
| • | Recline forward terminal A |
| • | Recline rearward terminal B |
| ⇒ | If the control circuits are not in the correct cavities, make the appropriate changes. |
| • | 5-volt reference terminal A |
| • | Low reference terminal D |
| ⇒ | If the 5-volt reference and low reference circuits are not in the correct cavities, make the appropriate changes. |
B2356, B2366, B2376
- Ignition OFF, disconnect the X1 harness connector at the driver seat adjuster motor assembly.
- Verify that the appropriate control circuits listed below are in the correct harness connector cavities:
- Disconnect the appropriate X2, X3, X4 harness connector at the driver seat adjuster motor assembly.
- Verify that the appropriate 5-volt reference and low reference circuits listed below are in the correct harness connector cavities:
- If all circuits test normal, replace the MSM.
| • | Front vertical motor up control terminal C |
| • | Front vertical motor down control terminal D |
| • | Rear vertical motor up control terminal E |
| • | Rear vertical motor down control terminal F |
| • | Seat horizontal motor forward control terminal A |
| • | Seat horizontal motor rearward control terminal B |
| ⇒ | If the control circuits are not in the correct cavities, make the appropriate changes. |
| • | Front vertical sensor 5-volt reference terminal C |
| • | Front vertical sensor low reference terminal A |
| • | Rear vertical sensor 5-volt reference terminal C |
| • | Rear vertical sensor low reference terminal A |
| • | Seat horizontal sensor 5-volt reference terminal A |
| • | Seat horizontal sensor low reference terminal C |
| ⇒ | If the 5-volt reference and low reference circuits are not in the correct cavities, make the appropriate changes. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for MSM replacement, setup, and programming
