DTC B1860 Driver Lumbar Vert Sensor CKT Malf w/o AM3
Circuit Description
The position sensor 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. The sensor also has a signal circuit that is wired 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.
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 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 MIL/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 V and 4.75 V during one cycle of checking the MSM inputs.
Diagnostic Aids
| • | If the 5 volt reference circuit is shorted to ground multiple codes will set. |
| • | If the 5 volt reference circuit is open at the massage module (AM3) multiple codes will set. |
| • | If the sensor ground circuit is open multiple codes will set. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Tests for the proper operation of the circuit in the low voltage range.
-
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.
-
Tests for a short to voltage in the 5 volt reference circuit.
-
Tests for a high resistance or an open in the ground circuit.
-
This step verifies the repair.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Power Seat Systems? | -- | ||
2 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is within the specified range? | 0.25-4.75 V | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is less than the specified value? | 0.25 V | |||
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is greater than the specified value? | 4.75 V | |||
Does the voltage measure less than the specified value? | 5.50 V | |||
6 |
Does the resistance measure less than the specified value? | 5 ohms | ||
7 | Test the 5 volt reference circuit of the lumbar vertical sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
8 | Test the 5 volt reference circuit of the lumbar vertical 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? | -- | ||
9 | Test the signal circuit of the lumbar vertical 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? | -- | ||
10 | Test the signal circuit of the lumbar vertical sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
11 |
Did you find and correct the condition? | -- | ||
12 | Inspect for poor connections at the harness connector of the lumbar vertical sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
13 | 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? | -- | ||
14 | Replace the seat lumbar vertical sensor. Refer to Front Seat Lumbar Support Replacement . Did you complete the replacement? | -- | -- | |
15 | Replace the memory seat module. Refer to Memory Seat Control Module Replacement . Did you complete the replacement? | -- | -- | |
Does the DTC reset? | -- | System OK |
DTC B1860 Driver Lumbar Vert Sensor CKT Malf with AM3
Circuit Description
The sensor that sets this diagnostic trouble code (DTC) monitors the seat lumbar vertical position. The sensor 5 V reference and ground are supplied by the memory seat module (MSM). The sensor output signal is sent directly to the massage module. The massage module checks this signal to determine seat position and then relays the information to the MSM. During lumbar massage operation, the massage module sends a simulated lumbar vertical position signal to the MSM. This prevents the MSM from seeing the lumbar up/down motion and erroneously setting a code.
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 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 MIL/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 V and 4.75 V during one cycle of checking the MSM inputs.
Diagnostic Aids
| • | If the 5 volt reference circuit is shorted to ground multiple codes will set. |
| • | If the 5 volt reference circuit is open at the massage module (AM3) multiple codes will set. |
| • | If the sensor ground circuit is open multiple codes will set. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Tests for the proper operation of the circuit in the high voltage range.
-
Tests for the proper operation of the circuit in the low voltage range.
-
This step verifies the repair.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Power Seat Systems? | -- | ||
2 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is within the specified range? | 0.25-4.75 V | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
Does the voltage measure within the specified range? | 4.50-5.50 V | |||
4 | Measure the voltage from the 5 volt reference circuit of the lumbar vertical sensor to the ground circuit of the lumbar vertical sensor. Does the voltage measure within the specified range? | 4.50-5.50 V | ||
5 | Measure the voltage from the 5 volt reference circuit of the massage module to a good ground. Does the voltage measure within the specified range? | 4.50-5.50 V | ||
6 | Measure the voltage from the battery positive voltage circuit of the massage module to a good ground. Does the voltage measure within the specified range? | 9-16 V | ||
With a scan tool, observe the Lumbar Vertical Sensor parameter. Does the scan tool indicate that the Lumbar Vertical Sensor parameter is greater than the specified value? | 4.75 V | |||
8 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is less than the specified value? | 0.25 V | ||
9 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is less than the specified value? | 0.25 V | ||
10 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is greater than the specified value? | 4.50 V | ||
11 | Test the 5 volt reference circuit of the lumbar vertical sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | 4.50 V | ||
12 | Test the 5 volt reference circuit of the lumbar vertical 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? | -- | ||
13 | Test the signal circuit of the lumbar vertical 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? | -- | ||
14 | Test the vertical position sensor output circuit of the massage module 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? | -- | ||
15 | Test the vertical position sensor output circuit of the massage module for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
16 | Test the signal circuit of the lumbar vertical sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
17 |
Did you find and correct the condition? | -- | ||
18 | Inspect for poor connections at the harness connector of the lumbar vertical sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
19 | Inspect for poor connections at the harness connector of the massage module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
20 | 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? | -- | ||
21 | Repair the open in the battery positive voltage circuit of the masage module. Did you complete the repair? | -- | -- | |
22 | Replace the seat lumbar vertical sensor. Refer to Front Seat Lumbar Support Replacement . Did you complete the replacement? | -- | -- | |
23 | Replace the massage module. Refer to Massaging Lumbar Control Module Replacement . Did you complete the replacement? | -- | -- | |
24 | Replace the memory seat module. Refer to Memory Seat Control Module Replacement . Did you complete the replacement? | -- | -- | |
Does the DTC reset? | -- | System OK |
