Circuit Description
The position sensor that sets this diagnostic trouble code (DTC) is attached directly to the lumbar motor it monitors. It receives a 5 V 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
The MSM must be powered and can not have B1982-Battery Voltage High or B1983 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 low reference 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 low reference circuit is open multiple codes will set. |
Test Description
The numbers below refer to the step numbers on the diagnostic table:
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Lumbar Support Schematics | ||||
1 | Did you perform the Diagnostic System Check - Power Seat Systems? | -- | Go to Step 2 | |
2 |
Important:: When reconnecting the position sensor connector, be sure that the connector is connected in the proper direction. It is possible to reverse the connector and cause improper memory operation. Does the resistance measure within the specified range? | 9,000 ohms -11,000 ohms | Go to Step 3 | Go to Step 9 |
3 | Measure the resistance between the signal terminal of the sensor and the low reference terminal of the sensor. Does the resistance measure within the specified range? | 10,000 ohms-18,000 ohms | Go to Step 4 | Go to Step 9 |
4 | Test the 5 volt reference circuit of the position sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 5 |
5 | Test the 5 volt reference circuit of the position sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 6 |
6 | Test the signal circuit of the position sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 7 |
7 | Test the signal circuit of the position sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 |
8 | Test the low reference circuit of the position sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
9 | Inspect for poor connections at the harness connector of the appropriate lumbar position sensor. 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 13 | Go to Step 11 |
10 | Inspect for poor connections at the harness connector of the memory seat module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | 5 ohms | Go to Step 13 | Go to Step 12 |
11 | Replace the appropriate lumbar position sensor. Refer to Front Seat Lumbar Support Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
12 | Replace the memory seat module. Refer to Memory Seat Control Module Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
Does the DTC reset? | -- | Go to Step 2 | System OK | |
