B1850

DTC B1850

CIRCUIT 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 V reference and ground 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
The MSM must be powered and can not have B1327-Battery Voltage Low set as an active DTC for this DTC to set.

CONDITIONS FOR SETTING THE DTC
If the MSM sees the analog input from this sensor as either lower than 0.25 V or higher than 4.75 V, the sensor will be considered out of range and the MSM will set this DTC.

ACTION TAKEN WHEN THE DTC SETS
The MSM disables the memory recall and easy exit/entry action commands of the motor monitored by the sensor. The motor will respond to manual positioning commands.

CONDITIONS FOR CLEARING THE DTC
The MSM will clear the DTC as an active malfunction when it sees the analog input from this sensor as between 0.25 V and 4.75 V during one cycle of checking the MSM inputs.

DIAGNOSTIC AIDS
- All position sensors use common ground and 5 volt reference circuits.
- If the 5 volt reference circuit is shorted to voltage multiple codes will set.
- If the 5 volt reference circuit is shorted to ground multiple codes will set.
- If the sensor ground circuit is open multiple codes will set.

TEST DESCRIPTION

Steps 1-2:

Steps 3-5:

Steps 6-11:

Steps 12-16:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.
4. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
5. Tests for a short to voltage in the 5 volt reference circuit.
6. Tests for a high resistance or an open in the low reference circuit.
16. This step verifies the repair.