I am wondering if anyone has any direct experience with these 2 codes. The first one c1243 is "BPMV pump motor stalled". The 2nd one c1286 is "steering sensor bias malfunction".

These are the only 2 codes I have and they're both current. I have my "service ABS, traction control, active handling, etc" message that pops up every time I start the car.

I received a great PM from Bill Trussell who gave me the lowdown on the EBCM. It seems that the code c1214 is a definate sign that the EBCM is faulty.

I do not have this code, so do you guys think it still leans towards the EBCM? Or could it be the sensors on the steering/pump motor?

I haven't actually started to physically diagnose this problem yet, so if anyone has any ideas of where I should start looking/cleaning/testing, please let me know.

Thanks in advance.

 

Have you had an alignment recently or the steering rack removed? quite often the 1283/1286 appears if that happens. Do a search for procedure to correct if that was the case.

 

no, i had an alignment a couple years ago after i lowered the car by cutting the front bushings.

there was no issues after the alignment and the car rides as good as ever. the code issue is fairly recent.

 

ttt.

 

You need to check/clean/ensure continuity of the EBCM/BPMV power, ground and signal circuits and make some measurements on the SWPS. The following diagnostics are from the 2000 Service Manual. You can't do some of the things the Tech 2 would allow you to do but if you have a 10 Meg Ohm input impedance digital multimeter then you can make some of the resistance and voltage checks called for in the procedures.

DTC C1243 BPMV Pump Motor Stalled

Circuit Description
When the pump motor relay is grounded by the EBCM, it closes and provides battery voltage to operate the pump.

Conditions for Setting the DTC
DTC C1243 can be set when the pump motor relay has been commanded off after the pump motor has been on. A malfunction has occurred if the pump motor was on, and the EBCM sensed a stuck or slowly turning pump motor.

Action Taken When the DTC Sets
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.

Indicators that turn on:
ABS indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service ABS
Service Traction System
Service Active HNDLG (if equipped with Active Handling RPO JL4)
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
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.

3. Checks for good pump motor ground.

5. Checks for good pump motor ground through the BPMV.

DTC C1243 BPMV Pump Motor Stalled Step
Action
Value(s)
Yes
No

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

Step 2
Is DTC 1217 also set as a current DTC?
--
Go to DTC C1217 Pump Motor Relay Contact Circuit Open
Go to Step 3

Step 3
Turn the ignition switch to the OFF position.
Using the J 39200 DMM, measure the resistance between the pump motor ground stud and a good chassis ground.
Is the resistance within the range specified in the value(s) column?
0-2 ohms
Go to Step 4
Go to Step 9

Step 4
Disconnect the EBCM connector.
Remove the EBCM from the BPMV.
Inspect the EBCM to BPMV connector for conditions which could cause intermittents, such as damage, corrosion, poor terminal contact, or presence of brake fluid.
Is connector OK and cavity free of brake fluid?
--
Go to Step 5
Go to Step 6

Step 5
Install the J 41247 Pinout Box to the BPMV connector.
Using the J 39200 DMM, measure the resistance between the J 41247 terminal 8 and the pump motor ground stud.
Is the resistance within the range specified in the Value(s) column?
0.2-10 ohms
Go to Step 7
Go to Step 8

Step 6
If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary.
If brake fluid is present, replace BPMV and EBCM.
Is the replacement complete?
--
Go to Diagnostic System Check - ABS
--

Step 7
Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

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

Step 8
Replace the BPMV. Refer to Brake Pressure Modulator Valve (BPMV) Replacement .

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

Step 9
Repair open or high resistance in CKT 1250. Refer to Wiring Repairs in Wiring Systems.

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


DTC C1286 Steering/Lateral Accelerometer Sensor Bias Malfunction RPO JL4

Circuit Description
Steer angle centering is the process by which the EBCM calibrates the steering sensor output so that it reads zero when the steering wheel is centered. The initial steering wheel center position is calculated after driving 10 km/h (6 mph) for more than 10 seconds in a straight line on a fairly level surface. The EBCM uses the Yaw Rate Sensor, Lateral Accelerometer and Wheel Speed Sensors to tell if the vehicle is moving in a straight line. 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 EBCM 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 plus or minus 40 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
ABS and TCS remain enabled, Active Handling™ is disabled.

Indicators that turn on: Car Icon (TCS indicator)
Messages displayed on the DIC: Service Active HNDLG 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
It is very important to check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a flat surface.
It is very important to find out from the driver when the code was set, (when the SERVICE ACTIVE HNDLG message was activated). This information may help to duplicate the failure.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. Check connector C102 RH side rear of engine compartment for water intrusion or missing plugs, and that the connector is oriented horizontal to prevent water intrusion.
An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation. Refer to Testing for Electrical Intermittents in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Step 11. Recenters the Steering Wheel Position Sensor.

DTC C1286 Strg/Lateral Accel Sensor Bias Malf (RPO JL4) Step
Action
Value(s)
Yes
No

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

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

Step 3
Using a scan tool, read ABS/TCS/Active handling DTC(s).

Is DTC C1282 or DTC C1284 set as a current DTC?
--
Go to Applicable DTC Table. Go to Diagnostic Trouble Code (DTC) List/Type
Go to Step 4

Step 4
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 5
Go to Step 11

Step 5
Using a scan tool, perform the Steering Wheel Position Sensor Test. Refer to Scan Tool Diagnostics .

Are the analog and digital displays on the scan tool within plus or minus 5 degrees of each other at the center (zero) position?
--
Go to Step 6
Go to Step 12

Step 6
Perform the Diagnostic Test Drive while monitoring the Yaw Rate Sensor output in degrees/seconds on a scan tool. Refer to Diagnostic System Check - ABS .

Are the degrees/second displayed on the scan tool within the range specified in the value(s) column?
0-5 degrees/second
Go to Step 8
Go to Step 7

Step 7
Replace the Yaw Rate Sensor. Refer to Yaw Rate Sensor Replacement .

Is the replacement complete?
--
Go to Step 14
--

Step 8
With the ignition switch in the ON position and the engine off, monitor the Lateral Accelerometer output in voltage using a scan tool.

Is the voltage displayed on the scan tool within the range specified in the value(s) column?
2.3-2.7 V
Go to Step 14
Go to Step 9

Step 9
Replace the Lateral Accelerometer. Refer to Lateral Accelerometer Replacement .

Is the replacement complete?
--
Go to Step 14
--

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

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

Step 11
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 Inflatable Restraint Steering Wheel 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 13
Go to Step 12

Step 12
Replace the Steering Wheel Position Sensor. Refer to Steering Shaft, Lower Bearing, and Jacket - Disassemble - Off Vehicle in Steering Wheel and Column.

Is the replacement complete?
--
Go to Step 14
--

Step 13
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 Inflatable Restraint Steering Wheel 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 14
--

Step 14
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?
--
Go to Step 10
Go to Diagnostic System Check - ABS

Bill

 

wow thanks bill! i'll look thru this procedure this weekend.