Circuit Description
The position sensor that sets this diagnostic trouble code (DTC) is either attached to the seat motor drive cable or directly to the motor it monitors. It receives a 5-volt reference and ground from the memory seat module (MSM). The sensor also has a analog output signal that is wired directly to the 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.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B2115 LF Head Restraint Up Switch Circuit |
| • | DTC B2116 LF Head Restraint Up Switch Circuit Performance |
| • | DTC B2117 LF Head Restraint Up Switch Circuit Low |
| • | DTC B2118 LF Head Restraint Up Switch Circuit High |
| • | DTC B2119 LF Head Restraint Up Switch Circuit Open |
| • | DTC B2120 LF Head Restraint Down Switch Circuit |
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 volts or higher than 4.75 volts, 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 the MSM sees the analog input from this sensor as between 0.25-4.75 volts during one cycle of checking the MSM inputs.
Diagnostic Aids
The position sensors use a common 5-volt reference circuit and a common sensor low reference circuit.
Test Description
The number below refer to the step numbers on the diagnostic table.
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 measure within the specified range? | 4.6-5.2 V | Go to Step 3 | Go to Step 7 | |
3 | Measure the voltage from the 5-volt reference circuit of the sensor connector to the low reference circuit of the sensor connector. Does the voltage measure within the specified range? | 4.6-5.2 V | Go to Step 4 | Go to Step 9 |
4 |
Does the voltage measure within the specified range? | 0.25-4.75 V | Go to Step 11 | Go to Step 5 |
5 | Test the signal circuit of the sensor for a short to ground, 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 14 | Go to Step 6 |
6 | Test the signal circuit of the sensor for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
7 | Test the 5-volt reference circuit of the sensor for a short to ground, 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 14 | Go to Step 8 |
8 | Test the 5-volt reference circuit of the sensor for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
9 | Test the low reference circuit of the 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 14 | Go to Step 11 |
10 | Inspect for poor connections at the harness connector of the 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 14 | Go to Step 12 |
11 | 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? | -- | Go to Step 14 | Go to Step 13 |
12 | Replace the inoperative sensor. Refer to the following: Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | 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 14 | -- |
14 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
