What does this mean for a code 28-TCS C 1284 Please help me!!!!
Thread Starter
Pro
Joined: Aug 2002
Posts: 549
Likes: 0
From: Mt. Pleasant PA
What does this mean for a code 28-TCS C 1284 Please help me!!!!
I know its a traction code......But what does the C1284 mean......I can't find it on my code sheet.....That's the code that comes up so it has to mean something
Any help would be a big big help.....The car is a 04 C5 Conv. Auto w/ no warrantee......Or I would have the dealer fix it.......By the way sometimes it comes on sometimes not....It seems to have a mind of its own......Is it a short or something if so were do I start to test at......
Any help would be a big big help.....The car is a 04 C5 Conv. Auto w/ no warrantee......Or I would have the dealer fix it.......By the way sometimes it comes on sometimes not....It seems to have a mind of its own......Is it a short or something if so were do I start to test at......
Safety Car
Joined: Jun 2003
Posts: 4,510
Likes: 240
From: Coconut Creek FL
Originally Posted by loweredvet
I know its a traction code......But what does the C1284 mean......I can't find it on my code sheet.....That's the code that comes up so it has to mean something Any help would be a big big help.....The car is a 04 C5 Conv. Auto w/ no warrantee......Or I would have the dealer fix it.......By the way sometimes it comes on sometimes not....It seems to have a mind of its own......Is it a short or something if so were do I start to test at......
Any help would be a big big help.....The car is a 04 C5 Conv. Auto w/ no warrantee......Or I would have the dealer fix it.......By the way sometimes it comes on sometimes not....It seems to have a mind of its own......Is it a short or something if so were do I start to test at......Found this by putting that code in the search field above...
DTC C1284 or C1285 Lateral Accelerometer Circuit
No idea what that is or does...
Melting Slicks
Joined: Nov 1999
Posts: 2,347
Likes: 857
From: MI
Cruise-In VI Veteran
DTC C1284 or C1285
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
C1284
The EBCM performs 7 different tests to detect a DTC condition. The numbers below correspond to the numbers in Conditions for Setting the DTC.
The lateral accelerometer sensor bias test runs with the ignition ON.
The lateral accelerometer sensor self test runs with the following conditions:
The ignition is ON.
The vehicle is stopped.
The lateral accelerometer sensor jerk test runs with the ignition ON.
The centered lateral accelerometer sensor test runs with the following conditions:
The ignition is ON.
The vehicle is stopped.
The lateral accelerometer sensor isolation test runs with the following conditions:
The ignition is ON.
DTC C1282 is not set.
The yaw rate is less than 8 degrees/second.
The above lateral accelerometer sensor isolation test runs with the VSES active.
The yaw rate sensor and lateral accelerometer sensor uncorrelated test with the following conditions:
The vehicle speed is greater than 10 km/h (6.2 mph) and less than 100 km/h (62 mph).
The centered yaw rate has a value that is positive and is greater than 10 degrees/second
C1285
The ignition is ON.
Conditions for Setting the DTC
C1284
The EBCM performs 7 different tests to detect a DTC condition. The numbers below correspond to the numbers in Conditions for Running the DTC.
The compensated bias value of the lateral accelerometer sensor is greater than 0.3 g.
The lateral accelerometer sensor performs a self test that results in an offset of 0.5 g. The EBCM compares the sensor output during the self test with the output following the test. The DTC sets when the lateral acceleration immediately following the self test is greater than the self test output minus 0.4 g.
The lateral jerk is greater than 16.5 g/second for 0.12 seconds more than 2 times within the ignition cycle.
The lateral acceleration is 0.4 g for 0.25 seconds.
The side slip error is greater than 0.5 g 30 times within a drive cycle.
The side slip error is greater than 0.5 g for 5 seconds. Under this condition, this DTC will set along with DTC C1281.
The oversteer term is negative for 2 seconds. The oversteer term is the yaw rate value times the lateral acceleration value. Under this condition, this DTC will set along with DTC C1281.
C1285
The lateral accelerometer input voltage is less than 0.15 volts or greater than 4.85 volts for 1 second.
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.
Tests for the proper operation of the circuit in the low voltage range.
Tests for the proper operation of the 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 the bias voltage of the lateral accelerometer sensor.
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
C1284
The EBCM performs 7 different tests to detect a DTC condition. The numbers below correspond to the numbers in Conditions for Setting the DTC.
The lateral accelerometer sensor bias test runs with the ignition ON.
The lateral accelerometer sensor self test runs with the following conditions:
The ignition is ON.
The vehicle is stopped.
The lateral accelerometer sensor jerk test runs with the ignition ON.
The centered lateral accelerometer sensor test runs with the following conditions:
The ignition is ON.
The vehicle is stopped.
The lateral accelerometer sensor isolation test runs with the following conditions:
The ignition is ON.
DTC C1282 is not set.
The yaw rate is less than 8 degrees/second.
The above lateral accelerometer sensor isolation test runs with the VSES active.
The yaw rate sensor and lateral accelerometer sensor uncorrelated test with the following conditions:
The vehicle speed is greater than 10 km/h (6.2 mph) and less than 100 km/h (62 mph).
The centered yaw rate has a value that is positive and is greater than 10 degrees/second
C1285
The ignition is ON.
Conditions for Setting the DTC
C1284
The EBCM performs 7 different tests to detect a DTC condition. The numbers below correspond to the numbers in Conditions for Running the DTC.
The compensated bias value of the lateral accelerometer sensor is greater than 0.3 g.
The lateral accelerometer sensor performs a self test that results in an offset of 0.5 g. The EBCM compares the sensor output during the self test with the output following the test. The DTC sets when the lateral acceleration immediately following the self test is greater than the self test output minus 0.4 g.
The lateral jerk is greater than 16.5 g/second for 0.12 seconds more than 2 times within the ignition cycle.
The lateral acceleration is 0.4 g for 0.25 seconds.
The side slip error is greater than 0.5 g 30 times within a drive cycle.
The side slip error is greater than 0.5 g for 5 seconds. Under this condition, this DTC will set along with DTC C1281.
The oversteer term is negative for 2 seconds. The oversteer term is the yaw rate value times the lateral acceleration value. Under this condition, this DTC will set along with DTC C1281.
C1285
The lateral accelerometer input voltage is less than 0.15 volts or greater than 4.85 volts for 1 second.
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.
Tests for the proper operation of the circuit in the low voltage range.
Tests for the proper operation of the 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 the bias voltage of the lateral accelerometer sensor.
Melting Slicks
Joined: Nov 1999
Posts: 2,347
Likes: 857
From: MI
Cruise-In VI Veteran
Step
Action
Values
Yes
No
Schematic Reference: ABS Schematics
Connector End View Reference: ABS Connector End Views
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 a scan tool, observe the Lateral Accelerometer Input parameter in the VSES data list.
Does the scan tool display that the Lateral Accelerometer Input parameter is within the specified range?
0.15-4.85 V
Go to Step 6
Go to Step 3
3
Turn OFF the ignition.
Disconnect the lateral accelerometer sensor connector.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Lateral Accelerometer Input parameter.
Does the scan tool display that the Lateral Accelerometer Input parameter is less than the specified value?
0.15 V
Go to Step 4
Go to Step 10
4
Turn OFF the ignition.
Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the lateral accelerometer sensor and the signal circuit of the lateral accelerometer sensor.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Lateral Accelerometer Input parameter.
Does the scan tool display that the Lateral Accelerometer Input parameter is greater than the specified value?
4.85 V
Go to Step 5
Go to Step 8
5
Disconnect the fused jumper wire.
Measure the voltage between the 5 volt reference circuit of the lateral accelerometer sensor and the low reference circuit of the lateral accelerometer.
Does the voltage measure less the specified value?
5.1 V
Go to Step 12
Go to Step 7
6
Does the scan tool display that the Lateral Accelerometer Input parameter is within the specified range?
2.3-2.7 V
Go to Diagnostic Aids
Go to Step 11
7
Test the 5 volt reference circuit of the lateral accelerometer 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 lateral accelerometer sensor 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 16
Go to Step 9
9
Test the signal circuit of the lateral accelerometer sensor 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 16
Go to Step 13
10
Test the signal circuit of the lateral accelerometer 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
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 lateral accelerometer sensor 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 16
Go to Step 12
12
Inspect for poor connections at the harness connector of the lateral accelerometer sensor. Refer to Testing for Intermittent 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 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 16
Go to Step 15
14
Replace the lateral accelerometer sensor. Refer to Lateral Accelerometer Replacement .
Did you complete the repair?
--
Go to Step 16
--
15
Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .
Did you complete the repair?
--
Go to Step 16
--
16
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
--------------------------------------------------------------------------------
Action
Values
Yes
No
Schematic Reference: ABS Schematics
Connector End View Reference: ABS Connector End Views
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 a scan tool, observe the Lateral Accelerometer Input parameter in the VSES data list.
Does the scan tool display that the Lateral Accelerometer Input parameter is within the specified range?
0.15-4.85 V
Go to Step 6
Go to Step 3
3
Turn OFF the ignition.
Disconnect the lateral accelerometer sensor connector.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Lateral Accelerometer Input parameter.
Does the scan tool display that the Lateral Accelerometer Input parameter is less than the specified value?
0.15 V
Go to Step 4
Go to Step 10
4
Turn OFF the ignition.
Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the lateral accelerometer sensor and the signal circuit of the lateral accelerometer sensor.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the Lateral Accelerometer Input parameter.
Does the scan tool display that the Lateral Accelerometer Input parameter is greater than the specified value?
4.85 V
Go to Step 5
Go to Step 8
5
Disconnect the fused jumper wire.
Measure the voltage between the 5 volt reference circuit of the lateral accelerometer sensor and the low reference circuit of the lateral accelerometer.
Does the voltage measure less the specified value?
5.1 V
Go to Step 12
Go to Step 7
6
Does the scan tool display that the Lateral Accelerometer Input parameter is within the specified range?
2.3-2.7 V
Go to Diagnostic Aids
Go to Step 11
7
Test the 5 volt reference circuit of the lateral accelerometer 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 lateral accelerometer sensor 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 16
Go to Step 9
9
Test the signal circuit of the lateral accelerometer sensor 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 16
Go to Step 13
10
Test the signal circuit of the lateral accelerometer 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
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 lateral accelerometer sensor 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 16
Go to Step 12
12
Inspect for poor connections at the harness connector of the lateral accelerometer sensor. Refer to Testing for Intermittent 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 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 16
Go to Step 15
14
Replace the lateral accelerometer sensor. Refer to Lateral Accelerometer Replacement .
Did you complete the repair?
--
Go to Step 16
--
15
Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .
Did you complete the repair?
--
Go to Step 16
--
16
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
--------------------------------------------------------------------------------
Le Mans Master
Joined: Jun 2004
Posts: 6,752
Likes: 3
From: Bethlehem PA
Now what I'd really pay some $$ for is a question to this:
How many C5 folks have had trouble with their EBCM units??
I replaced mine with 14k on the odo.
Dealer told me to stick it in my corn cob pipe and smoke it up.
They originally told me it was my tuners fault
and that something he programmed in was the cause.
Said tuner swapped another used unit in and all worked just fine.
Hmmmmmm. Original dealer told me they can not warrantee it as they did not install it.
Not enough harsh words in my repertoire to describe this frustration.
Called GM rep and they also told me to crap in my Derby (hat)
Scott
How many C5 folks have had trouble with their EBCM units??
I replaced mine with 14k on the odo.
Dealer told me to stick it in my corn cob pipe and smoke it up.
They originally told me it was my tuners fault
and that something he programmed in was the cause.Said tuner swapped another used unit in and all worked just fine.
Hmmmmmm. Original dealer told me they can not warrantee it as they did not install it.
Not enough harsh words in my repertoire to describe this frustration.
Called GM rep and they also told me to crap in my Derby (hat)
Scott
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ok I have to ask where is the EBCM located
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Joined: Jul 2007
Posts: 18,681
Likes: 47
From: Reno is so close to Hell you can see Sparks , State Of Confusion
St. Jude Donor '12-'13-'14
