DTC B1860 w/o AM3
Circuit Description
The position sensor that sets this diagnostic trouble code (DTC) 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 (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 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 ground 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 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 signal 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.
-
This step verifies the repair.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Lumbar Support Schematics Connector End View Reference: Power Seat Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Power Seat Systems? | -- | Go to Step 2 | |
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 | Go to Step 3 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is less than the specified value? | 2.00 V | Go to Step 4 | Go to Step 10 | |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is greater than the specified value? | 4.75 V | Go to Step 5 | Go to Step 8 | |
Does the voltage measure less than the specified value? | 5.50 V | Go to Step 6 | Go to Step 7 | |
6 |
Does the resistance measure less than the specified value? | 5 ohms | Go to Step 12 | Go to Step 11 |
7 | Test the 5 volt reference circuit of the lumbar vertical 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 16 | Go to Step 13 |
8 | Test the 5 volt reference circuit of the lumbar vertical position 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 16 | Go to Step 9 |
9 | Test the signal circuit of the lumbar vertical position 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 16 | Go to Step 13 |
10 | Test the signal circuit of the lumbar vertical 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 16 | Go to Step 13 |
11 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 |
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? | -- | Go to Step 16 | Go to Step 14 |
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? | -- | Go to Step 16 | Go to Step 15 |
14 | Replace the seat lumbar vertical sensor. Refer to Front Seat Lumbar Support Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
15 | Replace the memory seat module. Refer to Memory Seat Control Module Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
Does the DTC reset? | -- | Go to Step 2 | System OK | |
DTC B1860 with AM3
Circuit Description
The position sensor that sets this diagnostic trouble code (DTC) is attached to the lumbar directional motor it monitors. It receives a 5 V reference and ground 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 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 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 ground 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 5 volt reference circuit is open at the massage module 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 signal circuit in the high voltage range.
-
Tests for the proper operation of the signal circuit in the low voltage range.
-
This step tests the integrity of the lumbar vertical position sensor signal circuit. If the fuse in the jumper wire opens when you perform this test, a short to battery voltage may have occurred.
-
This step verifies the repair.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Lumbar Support Schematics Connector End View Reference: Power Seat Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Power Seat Systems? | -- | Go to Step 2 | |
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 | Go to Step 3 |
Does the voltage measure within the specified range? | 4.50-5.50 V | Go to Step 4 | Go to Step 18 | |
4 | Measure the voltage from the 5 volt reference circuit of the lumbar vertical sensor to the low reference circuit of the lumbar vertical sensor. Does the voltage measure within the specified range? | 4.50-5.50 V | Go to Step 5 | Go to Step 19 |
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 | Go to Step 6 | Go to Step 20 |
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? | 9-15 V | Go to Step 7 | Go to Step 21 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is greater than the specified value? | 4.75 V | Go to Step 8 | Go to Step 10 | |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is less than the specified value? | 0.25 V | Go to Step 15 | Go to Step 9 | |
9 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is less than the specified value? | 0.25 V | Go to Step 11 | Go to Step 13 |
10 |
Does the scan tool indicate that the Lumbar Vertical Sensor parameter is greater than the specified value? | 4.50 V | Go to Step 14 | Go to Step 12 |
11 | Test the lumbar position sensor signal circuit between the sensor and the massage module 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 25 | Go to Step 16 |
12 | Test the lumbar vertical position sensor signal circuit between the memory seat module and 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? | -- | Go to Step 25 | Go to Step 17 |
13 | Test the lumbar vertical position sensor signal circuit between the memory seat module and 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? | -- | Go to Step 25 | Go to Step 17 |
14 | Test the lumbar position sensor signal circuit between the sensor and the massage module for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 25 | Go to Step 16 |
15 | Inspect for poor connections at the harness connector of the lumbar vertical 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 25 | Go to Step 22 |
16 | 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? | -- | Go to Step 25 | Go to Step 23 |
17 | 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 25 | Go to Step 24 |
18 | Repair the open in the 5 volt reference circuit of the lumbar vertical position sensor. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 25 | -- |
19 | Repair the open in the low reference circuit of the lumbar vertical position sensor. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 25 | -- |
20 | Repair the open in the 5 volt reference circuit of the massage module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 25 | -- |
21 | Repair the open in the battery positive voltage circuit of the massage module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 25 | -- |
22 | Replace the seat lumbar vertical position sensor. Refer to Front Seat Lumbar Support Replacement . Did you complete the replacement? | -- | Go to Step 25 | -- |
23 | Replace the massage module. Refer to Massaging Lumbar Control Module Replacement . Did you complete the replacement? | -- | Go to Step 25 | -- |
24 | Replace the memory seat module. Refer to Memory Seat Control Module Replacement . Did you complete the replacement? | -- | Go to Step 25 | -- |
Does the DTC reset? | -- | Go to Step 2 | System OK | |
