Hallo,
wie Du ja schon schreibst trat der DTC zusammen mit der Meldung "Service Active Handling" auf. Hier liegt natürlich auch das Problem.
Ich habe Dir unten mal alle Infos bezüglich dieses DTC aus dem Service Manual reingeschrieben.
Die genaue Diagnose muss eine Fachwerkstatt mit einem Scantool durchführen, da ein Scantool im gegensatz zum DIC die genauen Spannungsdaten einer jeden Leitung herausmessen kann, um so evtl. Fehlerquellen auszuschliessen.
Einige mögliche Fehlerquellen können sein:
- Unterbrochene Leitung des Lateralen Beschleunigungsmesser
- Kurzschluss der Leitung des Lateralen Beschleunigungsmesser
- Defekter Lateraler Beschleunigungsmesser
- Korridierte Kontakte die hiermit in Verbindung stehen, oder hoher Widerstand in der Leitung zum Sensor
- Defektes ABS Controll Modul
Bei defektem ABS Controll Modul müssten aber noch weitere Codes vorhanden sein, ansonsten ist ABS und TCS weiterhin nicht außer Betrieb.
Viel Erfolg bei der Beseitigung des Problemes.
Grüße
Jochen
DTC C1284 or C1285 w/JL4
Circuit Description
The vehicle stability enhancement system (VSES) is activated by the 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 driver's 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.
The usable output voltage range for the lateral accelerometer and yaw rate sensors is 0.25-4.75 volts. The scan tool will report zero lateral acceleration or yaw rate as 2.5 volts with no sensor bias present. The sensor bias compensates for sensor mounting alignment errors, electronic signal errors, temperature changes, and manufacturing differences.
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
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/TCS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
The condition for the DTC is no longer present (the DTC is not current) and you used the On-Board Diagnostics Clear DTC function.
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.
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