• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Memory Seat/Mirror Sensor Low Reference | -- | B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01 | -- | -- |
5-Volt Reference | B1395 02, B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06 | B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06 | B1395 05, B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01 | -- |
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 | -- |
The memory seat module (MSM) supplies a 5-volt reference voltage to the driver seat horizontal, front vertical, rear vertical, recline, and both lumbar 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.
The MSM must be powered.
The reference voltage drops below 4.8 volts for more than 300 mS.
The reference voltage exceeds 5.2 volts for more than 300 mS.
All memory recall functions will be disabled.
• | The current DTC will clear and set the code to history, 3 seconds after the reference voltage returns to the normal operating range and the ignition is cycled OFF then back to ACC or RUN. |
• | The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred. |
• | All 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 DTC. |
• | An internal short to ground in one of the position sensors may set this DTC. |
Power Seat Connector End Views
⇒ | If greater than the specified value, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the MSM. |
⇒ | 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 4.8 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM. |
⇒ | If not within the specified range, replace the position sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for memory seat module replacement, setup, and programming |