DTC C1287 Steering Sensor Rate Malfunction. Buick LeSabre 2000

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1287 Steering Sensor Rate Malfunction

DTC C1287 Steering Sensor Rate Malfunction w/JL4

ABS Components
Vehicle Stability Enhancement System (w/JL4)
Handling ESD Sensitive Parts Notice

Circuit Description

The steering wheel position sensor supplies 2 analog inputs, Phase A and Phase B, to the EBCM. The 2 input signals are approximately 90 degrees out of phase. By interpreting the relationship between the 2 inputs, the EBCM can determine the position of the steering wheel and the direction of steering wheel rotation.

Steer angle centering is the process by which the EBCM calibrates the steering sensor output so that the output reads zero when the steering wheel is centered. Using the yaw rate input, lateral accelerometer input, and wheel speed sensor inputs, the initial steering center position is calculated after driving greater than 10 km/h (6 mph) for more than 10 seconds in a straight line on a level surface.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

One of the following conditions occur:

•	The steering wheel position sensor is synchronized and the steer rate (speed that the steering wheel appears to be turning) is greater than 1100 degrees/second.

•	The steer rate is less than 10 degrees/second and the difference in the phase angle between Phase A and Phase B is greater than 20 degrees.

•	The 2 steering sensor signals (Phase A and Phase B) do not agree for 1 second. Under this condition, this DTC will set along with DTC C1281.

Action Taken When the DTC Sets

•	The EBCM disables the VSES for the duration of the ignition cycle.

•	The DIC displays the SERVICE STABILITY SYSTEM message.

•	The ABS/TCS remains functional.

Conditions for Clearing the DTC

•	The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

•	The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

•	During diagnosis, park the vehicle on a level surface.

•	Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface.

•	Find out from the driver under what conditions the DTC was set (when the DIC displayed the SERVICE STABILITY SYSTEM message). This information will help to duplicate the failure.

•	The Snapshot function on the scan tool can help find an intermittent DTC.

Test Description

The number below refers to the step number on the diagnostic table.

This step performs the Steering Position Sensor Test to see if the steering wheel position sensor (SWPS) is operating properly.

Tests for the proper operation of the Phase A circuit in the low voltage range.

Tests for the proper operation of the Phase B circuit in the low voltage range.

Tests for the proper operation of the Phase A 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 the proper operation of the Phase B 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.

Step

Action

Value(s)

Yes

Did you perform the ABS Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, perform the Steering Position Sensor Test in DRP/ABS/TCS/TIM/VSES Special Functions. Refer to Scan Tool Diagnostics .

Did the steering wheel position sensor (SWPS) pass the test?

Go to Diagnostic Aids

Go to Step 3

Turn OFF the ignition.
Disconnect the steering wheel position sensor (SWPS) connector.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Dual Analog SWPS Input A parameter.

Does the scan tool indicate the Dual Analog SWPS Input A parameter is less than the specified value?

0.15 V

Go to Step 4

Go to Step 13

With the scan tool, observe the Dual Analog SWPS Input B parameter.

Does the scan tool indicate the Dual Analog SWPS Input B parameter is less than the specified value?

0.15 V

Go to Step 5

Go to Step 14

Turn OFF the ignition.
Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the steering wheel position sensor (SWPS) and the Phase A signal circuit of the steering wheel position sensor (SWPS).
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Dual Analog SWPS Input A parameter.

Does the scan tool indicate that the Dual Analog SWPS Input A parameter is greater than the specified value?

4.85 V

Go to Step 6

Go to Step 10

Turn OFF the ignition.
Disconnect the fused jumper wire.
Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the steering wheel position sensor (SWPS) and the Phase B signal circuit of the steering wheel position sensor (SWPS).
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Dual Analog SWPS Input B parameters.

Does the scan tool indicate that the Dual Analog SWPS Input B parameter is greater than the specified value?

4.85 V

Go to Step 7

Go to Step 10

Disconnect the fused jumper wire.
Measure the voltage between the 5 volt reference circuit of the steering wheel position sensor (SWPS) and the ground circuit of the steering wheel position sensor (SWPS).

Does the voltage measure less the specified value?

5 V

Go to Step 8

Go to Step 9

Turn OFF the ignition.
Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
Measure the resistance from the ground circuit of the steering wheel position sensor (SWPS) to a good ground.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 16

Go to Step 15

Test the 5 volt reference circuit of the steering wheel position sensor (SWPS) 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 20

Go to Step 17

Test the 5 volt reference circuit of the steering wheel position sensor (SWPS) for the following conditions:

•

An open

•	A short to ground

•	A high resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 11

Test the Phase A signal circuit of the steering wheel position sensor (SWPS) for the following conditions:

•

An open

•	A short to ground

•	A high resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 12

Test the Phase B signal circuit of the steering wheel position sensor (SWPS) for the following conditions:

•

An open

•	A short to ground

•	A high resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 17

Test the Phase A signal circuit of the steering wheel position sensor (SWPS) 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 20

Go to Step 17

Test the Phase B signal circuit of the steering wheel position sensor (SWPS) 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 20

Go to Step 17

Important: Removing battery voltage or ground from the EBCM will result in the following conditions:

•	Loss of the TIM learned tire inflation configuration parameters

•	Set DTC C1245 Low Tire Pressure Detected

When the diagnosis is complete, inspect the tire pressures and perform the TIM reset. Refer to Tire Inflation Monitor Resetting in Tire Pressure Monitoring.

Disconnect the EBCM harness connector.
Install the J 39700 universal pinout box using the J 39700-300 cable adapter to the EBCM harness connector only.
Test the ground circuit of the steering wheel position sensor (SWPS) 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 20

Go to Step 17

Inspect for poor connections at the harness connector of the steering wheel position sensor (SWPS). 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 20

Go to Step 18

Inspect for poor connections at the harness connector of the EBCM. 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 20

Go to Step 19

Replace the steering wheel position sensor (SWPS). Refer to Steering Shaft, Lower Bearing, and Jacket - Disassemble - Off Vehicle and Steering Shaft, Lower Bearing, and Jacket - Assemble - Off Vehicle in Steering Wheel and Column - Tilt.

Did you complete the replacement?

Go to Step 20

Important: Perform the setup procedure for the EBCM. An unprogrammed EBCM will result in the following conditions:

•	Inoperative or poorly functioning DRP/ABS/TCS/VSES/VES/TIM (if equipped)

•	Set DTC C1248 EBCM Turned the Red Brake Warning Indicator On

•	Set DTC C1255m3 EBCM Internal Malfunction

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the replacement?

Go to Step 20

Clear the DTCs using the scan tool.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK