Circuit Description
The recline seat motor is equipped with a internal hall effect sensor to determine seat position. The sensor is supplied with a reference voltage from the motor. A recline input circuit and ground circuit come from the memory seat module (MSM). The MSM receives a certain number of pulses from the sensor depending upon the position of the seat. The MSM then records the number of pulses so that the seat can be repositioned back to the same point that it was set at using the memory seat switches. The MSM then interprets the pulse input into a voltage reading for the data list on the scan tool.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B1826 Seat Recline Position Sensor Circuit Range/Performance
Conditions for Running the DTC
The MSM detects a switch signal active or a memory function request.
Conditions for Setting the DTC
The MSM detects the recline input circuit achieves the max or minimum pulse input.
Action Taken When the DTC Sets
Memory functions will be disabled for the recline motor as long as the fault is current.
Conditions for Clearing the DTC
| • | The DTC will be current for as long as the fault is present. |
| • | When the fault is no longer present the DTC will be a history status code. |
| • | The history DTC will be cleared after 100 error-free ignition cycles, or by using the scan tool clearing DTCs feature. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Driver Seat Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool indicate that the Recline Sensor Data parameter is within the specified range? | 0-5 V | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the scan tool indicate that the Position Sensor parameter is less than the specified value? | 0.75 V | Go to Step 4 | Go to Step 9 |
4 |
Does the scan tool indicate that the Recline Position Sensor parameter is greater than the specified value? | 4.75 V | Go to Step 5 | Go to Step 6 |
5 | Connect a test lamp between the ground circuit at the recline motor for the recline position sensor and battery positive voltage. Did the test lamp illuminate? | -- | Go to Step 7 | Go to Step 10 |
6 | Test the recline input circuit for a short to ground, open, or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | 5 ohms | Go to Step 13 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the recline motor. 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 |
8 | Inspect for poor connections at the harness connector of the seat adjuster memory 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 13 | Go to Step 12 |
9 | Repair the short to battery positive voltage in the recline input circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | -- |
10 | Repair the open in the ground circuit of the recline sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | -- |
11 | Replace the recline motor. Did you complete the replacement? | -- | Go to Step 13 | -- |
12 | Replace the seat adjuster memory module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
