I was driving down the road yesterday and the ABS light came on. Codes are as follows. Only 2 of them were present before this incident (C1287, C1288). Do you think there's a common issue between these codes? Thanks for any assistance!

TCS
C1221-LF Wheel Speed Sensor
C1222-RF Wheel Speed Sensor
C1248-?
C1255-EBTCM Internal Malfunction
C1267-RR Inlet Valve Solenoid
C1287-Steering Sensor Rate Malfunction
C1288-?

I just cleared the codes, but didn't move the car, and c1267 was the only one to come back up.

 

Paging Dr. Curlee.....Dr. Curlee.........

 

I did some reading and believe I need to flush the brake fluid. I just made a trip to the Socialist Republic of Walmart for some DOT3, and will bleed them out in the morning. Seems that the EBCM code could be related.

As for the wheel speed sensor codes it clicked that I should have those because the car was just on the dyno. Cleared and hasn't came back.

 

Flushing the brake fluid will more than likely not do anything for the solenoid code in the BPMV since you need to do an automated bleed of the system to get brake fluid through the BPMV.

Bill

 

Let me guess I need a Tech 2 for that?? Will Snap-On's diagnostic tool do the same thing? I don't know the part number, but it looks like an Xbox and has a keychain of slot cards for different car types?

 

Well,,,,,,,,,,, you really don't. I exercise my pump and solenoids by activating my AH and anti-lock braking system on wet roads. It is easy to do, and causes a LOT less wear and tear on the car and does a great job getting the system exercised.

Work the system and clear the DTCs and see if That helps

BC

 

I see. So I will still be able to activate the ABS with the light on?

 

See if you can clear the light and immediately try activating the ANTILOCK. It takes a little while for the computer to figure out theres an issue and set the DTC.

Hope it works for you..

BC

 

I looked up the other DTCs. Man,,,,, ,, Are you SURE that the main EBTCM main cable ic properly connected or the wires are not damaged???????????? If it were me,,, I would check.



DTC C1248
Circuit Description
The dynamic rear proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the mechanical proportioning valve in the base brake system. The DRP control system is part of the operating software in the EBCM. The DRP uses active control with the existing ABS in order to regulate the vehicle's rear brake pressure.

Conditions for Running the DTC
One or more faults have been detected by the EBCM in the ABS/TCS systems.

Conditions for Setting the DTC
One of the following conditions exits:

DTC C1236 sets and ignition voltage is less than 8.5 volts.
DTC C1254 or C1255 sets.
DTCs C1265 and C1267 set.
Two wheel speed sensor DTCs on the same axle set.
Action Taken When the DTC Sets
The EBCM disables the DRP for the duration of the ignition cycle.
The red Brake warning indicator turns ON.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Use this DTC in order to differentiate which of the following conditions is present:
The EBCM turned ON the red Brake warning indicator.
The instrument cluster turned ON the red Brake warning indicator due to low brake fluid in the master cylinder reservoir.
The instrument cluster turned ON the red Brake warning indicator due to the application of the park brake.
Diagnose any other ABS DTCs that set along with this DTC.
Test Description
The number below refers to the step number on the diagnostic table.

Verifies whether other ABS/TCS/VSES DTCs are set.

Step
Action
Yes
No

Schematic Reference: ABS Schematics

1
Did you perform the ABS Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - ABS

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
Select the display DTCs function on the scan tool for the EBCM.
Does the scan tool display any ABS/TCS/VSES DTCs?
Go to Diagnostic Trouble Code (DTC) List
Go to Step 3

3
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
Go to Step 2
Go to Testing for Intermittent and Poor Connections in Wiring System



--------------------------------------------------------------------------------
Document ID# 674151
2002 Chevrolet Corvette


DTC C1287 or C1288
Circuit Description
The vehicle stability enhancement system (VSES) is activated by the electronic brake control mdoule (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the drivers steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.

The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the ABS pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.

Conditions for Running the DTC
The ignition is ON.

Conditions for Setting the DTC
C1287
One of the following conditions exists:

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 80 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.
C1288
One of the following conditions exists:

Both Phase A and Phase B are greater than 4.9 volts for 1.6 seconds.
Both Phase A and Phase B are less than 0.2 volts for 1.6 seconds.
The difference in the changes in Phase A and Phase B is greater than 35.2 degrees for 9.76 milliseconds.
Action Taken When the DTC Sets
The EBCM disables the VSES for the duration of the ignition cycle.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the Service Active Handling message.
The ABS 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 EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
The scan tool may display 2 additional characters after the DTC. Take note of the 2 character code and any other DTCs that are set. The 2 character code is an engineering aid used in order to determine the specific criteria which caused the DTC to set.
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 Active Handling 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 numbers below refer to the step numbers on the diagnostic table.

Perform the Steering Position Sensor Test in order to verify if the steering wheel position sensor (SWPS) is operating properly.

Tests for the proper operation of the steering wheel position signal A circuit in the low voltage range.

Tests for the proper operation of the steering wheel position signal B circuit in the low voltage range.

Tests for the proper operation of the steering wheel position signal 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 steering wheel position signal 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 low reference circuit.

Step
Action
Values
Yes
No

Schematic Reference: ABS Schematics

1
Did you perform the ABS Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check - ABS

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, perform the Steering Position Sensor Test.
Did the SWPS pass the test?
--
Go to Diagnostic Aids
Go to Step 3

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 in the VSES data list.
Does the scan tool indicate the Dual Analog SWPS Input A parameter is less than the specified value?
0.2 V
Go to Step 4
Go to Step 13

4
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?
0.2 V
Go to Step 5
Go to Step 14

5
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 signal A 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?
4.9 V
Go to Step 6
Go to Step 10

6
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 signal B 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 parameter.
Does the scan tool indicate that the Dual Analog SWPS Input B parameter is greater than the specified value?
4.9 V
Go to Step 7
Go to Step 10

7
Disconnect the fused jumper wire.
Measure the voltage between the 5 volt reference circuit of the steering wheel position sensor (SWPS) and the low reference 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

8
Turn OFF the ignition.
Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical.
Measure the resistance from the low reference 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

9
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

10
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

11
Test the signal A 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

12
Test the signal B 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

13
Test the signal A 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

14
Test the signal B 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

15
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 low reference 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

16
Inspect for poor connections at the harness connector of the steering wheel position sensor (SWPS). Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 20
Go to Step 18

17
Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 20
Go to Step 19

18
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 repair?
--
Go to Step 20
--

19
Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Did you complete the repair?
--
Go to Step 20
--

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



--------------------------------------------------------------------------------
Document ID# 670707
2002 Chevrolet Corvette

 

Yes the cable is properly connected. Car is at the dealership now to get brake lines and ABS flushed. I tried to exercise the ABS, but coudn't get the code to clear while driving. I even turned the car off then back on while rolling and it wouldn't clear. I'll post back up after lunch. Thanks!

 

Just talked to the mechanic (who is also a friend). He says he's seen this before the issue is electrical and is in the EBCM. Is this a symptom of the cold solder joint/bad relay issue?

 

Might help..

http://forums.corvetteforum.com/c5-t...r-fleabay.html

 

THIS "C1255-EBTCM Internal Malfunction" is the one thats making things BAD! Who knows what it is unless you rip it apart and check all the circuits with a 2M microscope

I did that very process and I was ASHAMED of the soldering I saw on my replaced EBTCM unit








Ive seen water inside the modules do some really weird stuff.

Hard to say.

BC

 

C1267 is the code I keep getting. While searching I noticed somebody having the same issue as me, but no solution was posted. I've sent him a message, but no reply. Link