ok. i have 2 codes that continue to come back over and over after reseting.
C1281 Steering Sensor Uncorrelated Malfunction
C1286 Steering Sensor Bias Malfunction
obviously these are related. anyone have any advice where to look or whats the possibility's?
ive searched the forum and found a procedure to check the sensor steering sensor. was just wondering what you guys would think

 

Would help if we knew the year and if you have active handling or not. Troubleshooting methods depend on this.

 

Sounds like your SWPS is BAD. Unless you have a TECH II or are confortable using a DVM to check both phases of the sensor for correct output,,Just change it.

BC

 

Just went through this myself. I also had C1287 code along with active handling error. It was the SWPS (Steering Wheel Position Switch) as noted by Bill.

 

98. no active handling. and yes im comfortable w/ a dvm i use one on a dailey basis

 

From the 98 service manual, it's kinf of hard to read in this format:
DTC C1281 Steering Sensor Uncorrelated Malfunction Without RPO JL4

Circuit Description
The EBTCM uses four inputs from the Steering Wheel Position sensor:

Phase A digital input
Phase B digital input
Index pulse
Analog input
This information is used to calculate three things:

The front wheels position when centered.
The front wheels position when turning.
The vehicles lateral acceleration.
The EBTCM runs a centering routine when the vehicle speed goes above 30 Km/h (18 mph). When the vehicle reaches 30 Km/h (18 mph), the EBTCM monitors the Steering Wheel Position Sensor inputs (Phase A, Phase B and Analog voltage) to see if the steering wheel is moving. If the steering wheel is not moving for a set period of time then the EBTCM assumes the vehicle is going in a straight line. At this point, the EBTCM looks at the analog voltage signal and reads the voltage. This voltage normally around 2.5V, is then considered the center position and the digital degrees also become zero at the same time. This centering routine is necessary to compensate for wear in the steering and suspension. Wear in the steering and suspension can result in a change in the relationship between the steering wheel and the front wheels. By running the centering routine the EBTCM can compensate for these changes by changing the digital and analog center position.

The EBTCM uses the digital input (Phase A and Phase B) from the Steering Wheel Position Sensor to calculate the direction the driver of the vehicle is trying to steer during an ABS event. This information is also used to calculate the vehicles lateral acceleration for Magnasteer®2.

Conditions for Setting the DTC
DTC C1281 will set when the digitally derived centered angle differs from the analog derived angle by 27 degrees or more for a period of 5 seconds.
DTC C1281 will set if the index pulse is not seen between ± 37 degrees or is seen between -185 degrees and -37 degrees or 37 degrees and 185 degrees of steering wheel travel.
DTC C1281 will set if phase A and or phase B are shorted.
Action Taken When the DTC Sets
Magnasteer®2 is disabled, ABS/TCS remains active.

Messages displayed on the DIC:

Service Vehicle Soon

Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
If the analog Steering Wheel Position Sensor input is missing then DTC C1288 will set.
If the Steering Wheel Position Sensor 5 volt supply or the Steering Wheel Position ground is missing DTC C1288 will set.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Wiring Systems.
Test Description
The numbers below refer to step numbers on the diagnostic table.

Checks for the analog voltage to change, if the analog voltage does not change DTC C1281 will set.

Checks if the digital Phase A and Phase B are changing state from high to low.

checks to see if the analog and digital readings are ± 27° of each other.

Checks to see if the EBTCM is supplying the pull up voltage for Phase A.

Checks to see if the EBTCM is supplying the pull up voltage for Phase B.

Checks to see if the EBTCM is supplying the pull up voltage for the Index pulse.

DTC C1281 Steering Sensor Uncorrolated Malfunction Step
Action
Value(s)
Yes
No

1
Was the Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check

2
Is this vehicle equipped with Active Handling (RPO JL4)?
--
Go to DTC C1281 Active Handling Sensors Uncorrelated
Go to Step 3

3
Turn the ignition switch to the ON position, engine off.
Using a scan tool read ABS/TCS DTC(s).
Are any of the following DTC(s) present, C1286 or C1288?
--
Go to Applicable DTC table. Refer to Diagnostic Trouble Code (DTC) List
Go to Step 4

4
Cycle the ignition switch from the OFF to ON position.
Using a scan tool in the Data List monitor the Analog Steer Sensor Voltage as you rotate the steering wheel from left to right.
Does the Analog Steer Sensor Voltage change as the steering wheel is rotated?
--
Go to Step 5
Go to Step 7

5
Using a scan tool in the Data List monitor the Digital SWPS Input as you rotate the steering wheel from left to right.

Does the Digital SWPS Input change as the steering wheel is rotated?
--
Go to Step 6
Go to Step 11

6
Using a scan tool in the Data List monitor the Analog Steer Sensor Voltage and the Digital SWPS Input.
Rotate the steering wheel until the Digital SWPS Input reads 50 degrees.
Does the Analog Steer Sensor Voltage read within the range specified in the value(s) column?
2.7-3.3 V
Go to Step 8
Go to Step 9

7
Turn the Ignition switch to the OFF position.
Disconnect the EBTCM.
Install the J 39700 Universal Pinout Box using the J 39700-25 cable adapter between the EBTCM harness connector and the EBTCM.
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 23 of J 39700 as an assistant rotates the steering wheel.
Does the voltage change as the steering wheel is rotated?
--
Go to Step 10
Go to Step 9

8
Rotate the steering wheel in either direction while monitoring the Digital SWPS Index Pulse with a scan in Data List.

Does the Digital SWPS Index Pulse go HIGH within ± 37 degrees of steering center while rotating the steering wheel?
--
Go to Step 10
Go to Step 13

9
Replace the Steering Wheel Position Sensor. Refer to Steering Wheel Position Sensor Replacement in Steering Wheel and Column.

Is the replacement complete?
--
Go to Diagnostic System Check
--

10
Replace the EBTCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Is the replacement complete?
--
Go to Diagnostic System Check
--

11
Turn the Ignition switch to the OFF position.
Disconnect the EBTCM.
Install the J 39700 Universal Pinout Box using the J 39700-25 cable adapter between the EBTCM harness connector and the EBTCM.
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 20 of J 39700 as an assistant rotates the steering wheel.
Does the voltage toggle between 0 and Battery volts as the steering wheel is rotated?
--
Go to Step 12
Go to Step 20

12
Using J 39200 DMM, measure the voltage at terminal 4 of J 39700 as an assistant rotates the steering wheel.

Does the voltage toggle between 0 and Battery volts as the steering wheel is rotated?
--
Go to Step 10
Go to Step 26

13
Turn the Ignition switch to the OFF position.
Disconnect the EBTCM.
Install the J 39700 Universal Pinout Box using the J 39700-25 cable adapter between the EBTCM harness connector and the EBTCM.
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 19 of J 39700 as an assistant rotates the steering wheel from the center position to the right.
Does the voltage toggle between 0 and Battery volts one time as the steering wheel is rotated to the right?
--
Go to Step 10
Go to Step 14

14
Turn the ignition switch to the OFF position.
Disconnect the J 39700-25 cable adapter from the EBTCM leaving the J 39700-25 cable adapter connected to the EBTCM harness connector.
Disconnect the Steering Wheel Position Sensor connector.
Using J 39200 DMM, measure the resistance between terminals 19 and B of J 39700 .
Is the resistance within the range specified within the value(s) column?
OL (infinite)
Go to Step 16
Go to Step 15

15
Repair short to ground in CKT 1765. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

16
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 19 of J 39700 .
Is the voltage within the range specified in the value(s) column?
Above 1 V
Go to Step 17
Go to Step 18

17
Repair short to voltage in CKT 1765. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

18
Turn the ignition switch to the OFF position.
Connect a jumper wire between terminals 19 and B of J 39700 .
Using J 39200 DMM, measure the resistance between the Steering Wheel Position Sensor harness connector terminal 5 and a good ground.
Is the resistance within the range specified in the value(s) column?
0-5 ohms
Go to Step 34
Go to Step 19

19
Repair open or high resistance in CKT 1765. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

20
Turn the ignition switch to the OFF position.
Disconnect the J 39700-25 cable adapter from the EBTCM leaving the J 39700-25 cable adapter connected to the EBTCM harness connector.
Disconnect the Steering Wheel Position Sensor connector.
Using J 39200 DMM, measure the resistance between terminals 20 and B of J 39700 .
Is the resistance within the range specified within the value(s) column?
OL (infinite)
Go to Step 22
Go to Step 21

21
Repair short to ground in CKT 1763. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

22
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 20 of J 39700 .
Is the voltage within the range specified in the value(s) column?
Above 1 V
Go to Step 23
Go to Step 24

23
Repair short to voltage in CKT 1763. Refer to Wiring Repairs in Wiring Systems

Is the repair complete?
--
Go to Diagnostic System Check
--

24
Turn the ignition switch to the OFF position.
Connect a jumper wire between terminals 20 and B of J 39700 .
Using J 39200 DMM, measure the resistance between the Steering Wheel Position Sensor harness connector terminal 3 and a good ground.
Is the resistance within the range specified in the value(s) column?
0-5 ohms
Go to Step 32
Go to Step 25

25
Repair open or high resistance in CKT 1763. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

26
Turn the ignition switch to the OFF position.
Disconnect the J 39700-25 cable adapter from the EBTCM leaving the J 39700-25 cable adapter connected to the EBTCM harness connector.
Disconnect the Steering Wheel Position Sensor connector.
Using J 39200 DMM, measure the resistance between terminals 4 and B of J 39700 .
Is the resistance within the range specified within the value(s) column?
OL (infinite)
Go to Step 28
Go to Step 27

27
Repair short to ground in CKT 1764. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

28
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 4 of J 39700 .
Is the voltage within the range specified in the value(s) column?
Above 1 V
Go to Step 29
Go to Step 30

29
Repair short to voltage in CKT 1764. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

30
Turn the ignition switch to the OFF position.
Connect a jumper wire between terminals 4 and B of J 39700 .
Using J 39200 DMM, measure the resistance between the Steering Wheel Position Sensor harness connector terminal 4 and a good ground.
Is the resistance within the range specified in the value(s) column?
0-5 ohms
Go to Step 33
Go to Step 31

31
Repair open or high resistance in CKT 1764. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Go to Diagnostic System Check
--

32
Reconnect the J 39700-25 cable adapter to the EBTCM leaving the J 39700-25 cable adapter connected to the EBTCM harness connector.
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 20 of J 39700 .
Is the voltage within the range specified in the value(s) column?
Battery volts
Go to Step 9
Go to Step 10

33
Reconnect the J 39700-25 cable adapter to the EBTCM leaving the J 39700-25 cable adapter connected to the EBTCM harness connector.
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 4 of J 39700 .
Is the voltage within the range specified in the value(s) column?
Battery volts
Go to Step 9
Go to Step 10

34
Reconnect the J 39700-25 cable adapter to the EBTCM leaving the J 39700-25 cable adapter connected to the EBTCM harness connector.
Turn the ignition switch to the ON position, engine off.
Using J 39200 DMM, measure the voltage at terminal 19 of J 39700 .
Is the voltage within the range specified in the value(s) column?
Battery volts

DTC C1286 Steering Sensor Bias Malfunction Without RPO JL4

Circuit Description
The EBTCM runs a centering routine when the vehicle speed goes above 30 Km/h (18 mph). When the vehicle reaches 30 Km/h (18 mph), the EBTCM monitors the Steering Wheel Position Sensor inputs (Phase A, Phase B and Analog voltage) to see if the steering wheel is moving. If the steering wheel is not moving for a set period of time then the EBTCM assumes the vehicle is going in a straight line. At this point, the EBTCM looks at the analog voltage signal and reads the voltage. This voltage normally around 2.5V, is then considered the center position and the digital degrees also become zero at the same time. This centering routine is necessary to compensate for wear in the steering and suspension. Wear in the steering and suspension can result in a change in the relationship between the steering wheel and the front wheels. By running the centering routine the EBTCM can compensate for these changes by changing the digital and analog center position.

Conditions for Setting the DTC
DTC C1286 can be set after the centering routines completion if the bias value is ± 30 degrees from the previous bias value.
DTC C1286 can also be set at start up if the bias value was out of range on the last ignition cycle.
Action Taken When the DTC Sets
Magnasteer®2 is disabled, ABS/TCS remains active.

Messages displayed on the DIC:

Service Vehicle Soon

Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
Possible causes:

Steering wheel rotated with steering gear disconnected.
Faulty Steering Wheel Position Sensor.
Faulty EBTCM.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Recenters the Steering Wheel Position Sensor.

DTC C1286 Steering Sensor Bias Malfunction Step
Action
Value(s)
Yes
No

1
Was the Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check

2
Is this vehicle equipped with Active Handling (RPO JL4)?
--
Go to DTC C1286 Steering/Lateral Accelerometer Sensor Bias Malfunction
Go to Step 3

3
Point the front wheels straight ahead.
Using a scan tool check the Steering Wheel Position Sensor Analog voltage.
Is the voltage within the range specified within the value(s) column?
2-3 V
Go to Step 4
Go to Step 5

4
Replace the EBTCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Is the repair complete?
--
Go to Diagnostic System Check
--

5
Turn the ignition switch to the OFF position.
Disable the Supplemental Inflatable Restraint (SIR). Refer to Disabling the SIR System in SIR.
Remove the Inflatable Restraint Wheel Module Coil. Refer to Steering Wheel Inflator Module Coil Replacement in Steering Wheel and Column.
Remove the Intermediate Shaft. Refer to Intermediate Steering Shaft Replacement in Steering Wheel and Column.
Turn the ignition switch to the ON position, engine off.
Using a scan tool monitor the Steering Wheel Position Sensors analog voltage as you rotate the steering column shaft.
Turn the steering column shaft until the analog voltage is close to 2.5 volts.
Does the analog voltage move to or close to 2.5 volts?
--
Go to Step 7
Go to Step 6

6
Replace the Steering Wheel Position Sensor. Refer to Steering Wheel Position Sensor Replacement in Steering Wheel and Column.

Is the replacement complete?

Go to Diagnostic System Check
--

7
Leave the steering column shaft centered at 2.5 volts.
Turn the ignition switch to the OFF position.
Install the Intermediate Shaft. Refer to Intermediate Steering Shaft Replacement in Steering Wheel and Column.
Install the Inflatable Restraint Wheel Module Coil. Refer to Steering Wheel Inflator Module Coil Replacement in Steering Wheel and Column.
Enable the SIR. Refer to Enabling the SIR System in SIR.
Is the repair complete?
--
Go to Step 8
--

8
Turn the ignition switch to the ON position, engine off.
Using a scan tool clear DTC C1286.
Drive vehicle above 30 Km/h (18 mph) for several minutes.
Using a scan tool check for DTC C1286.
Did DTC C1286 set as a current DTC?