Circuit Description
The sensor that set this diagnostic trouble code (DTC) is attached to the seat directional 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 sensor signal circuit to the MSM. Then based on this voltage signal, the MSM determines the position of the seat.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B1826 Seat Recline Position Sensor Circuit Range/Performance |
| • | DTC B1851 Seat Lumbar Horizontal Position Sensor Circuit Range/Performance |
| • | DTC B1861 Seat Lumbar Vertical Position Sensor Circuit Range/Performance |
| • | DTC B2356 Seat Front Vertical Position Sensor Circuit Range/Performance |
| • | DTC B2366 Seat Rear Vertical Position Sensor Circuit Range/Performance |
| • | DTC B2376 Seat Assembly Horizontal Position Sensor Circuit Range/Performance |
Conditions for Running the DTC
| • | The MSM must be powered and cannot have B1327 - Battery Voltage Low set as a current DTC for this DTC to set. |
| • | This test will run only when the motors are active. |
Conditions for Setting the DTC
If the sensor signal received by the MSM from a motor being driven in a commanded direction changes by more than 10 counts or 0.2 volts in the wrong direction, the MSM will set this DTC.
Action Taken When the DTC Sets
| • | Current and History codes are set. |
| • | The MSM disables the affected motor during memory recall operations. |
| • | The affected motor will respond to manual positioning commands. |
Conditions for Clearing the DTC
The MSM will clear the DTC as an active DTC, whenever a manual switch is activated and the MSM senses that the voltage from the sensor signal changes by more than 2 counts or 0.04 volts in the correct direction.
Diagnostic Aids
All position sensors use common 5-volt reference and low reference circuits.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step checks the direction in which the volts change as the switch is activated. The voltage should increase for the forward or up position and decrease for the rearward or down position.
-
This step checks the polarity of the seat position sensor wiring.
-
This step checks the polarity of the seat motor wiring.
-
This step checks the polarity of the seat switch wiring.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Driver Seat Schematics Connector End View Reference: Power Seat Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the voltage increase? | -- | Go to Step 9 | Go to Step 3 | |
3 | Does the seat move in the commanded direction? | -- | Go to Step 4 | Go to Step 5 |
Verify that the seat position sensor wiring circuits are in the correct harness connector cavities. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 7 | |
Verify that the seat motor wiring circuits are in the correct harness connector cavities. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 6 | |
Verify that the seat switch wiring circuits are in the correct harness connector cavities. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 7 | |
7 | Inspect for poor connection at the harness connector of the memory seat module (MSM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
8 | Replace the MSM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
