Selecting Test Mode
WARNING: This page is about a different car, the 1996 Pontiac Grand Prix, 1996 Oldsmobile Cutlass Supreme, and 1996 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
Six test modes are available for diagnosing ABS/VES. Test modes are:
- Mode F0 (Data List) Mode continuously monitors wheel speed data, brake switch status, ABS/VES status, and other inputs and outputs. Data list can not be read if any DTCs are set.
- Mode F1 (DTC History) Mode displays DTC history data. Fault occurrence information is stored for first 5 DTCs stored and very last DTC stored. Fault occurrence information stored consists of DTC number, number of failure occurrences and number of ignition cycles since fault first and last occurred.
- Mode F2 (Diagnostic Trouble Codes) Mode displays ABS/VES DTCs. Both ignition cycle and history may be displayed or cleared.
- Mode F3 (Snapshot) Mode will help isolate intermittent problems by capturing data before and after fault condition. Snapshots cannot be read until all stored DTCs are cleared.
- If MANUAL TRIGGER is selected, Tech 1 will wait for ENTER to be pressed before storing data. Tech 1 stores data from 8 seconds before trigger and 8 seconds after trigger is activated. All stored information can be displayed and examined for conditions which might indicate a problem, but may not set a DTC.
- If AUTOMATIC TRIGGER is selected, Tech 1 will capture data which deviates from normal conditions but may not set a DTC, such as driving over bumpy roads or railroad tracks. Condition may be caused by loose connections or intermittent wiring problems causing signal to drop out momentarily. While Tech 1 is waiting for a trigger, ENTER or F9 key may be used to force a trigger.
- Mode F4 (Misc Tests) In this mode, Tech 1 performs various ABS/VES functional tests to help isolate problems during trouble shooting.
- Mode F5 (Motor Rehome) In this mode, EBCM is commanded to return all ABS modulator/motor pack assembly motors to home position (full open). This mode should always be used before bleeding brakes.
DIAGNOSTIC TROUBLE CODES (DTCS) (1)
| DTC | Definition | ||
|---|---|---|---|
| 43/C1243 | VES Steering Circuit Malfunction | ||
| 73/C1273 | VES Actuator Circuit Open Or Shorted To Ground | ||
| 74/C1274 | VES Actuator Circuit Shorted To Battery | ||
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