LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1992 >> Cherokee Limited >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Diagnosis - Aw-4 >> DRB-II Operating Modes >> System Test Mode
April 5, 2026: LEMON Manuals is launched! Read the announcement.

System Test Mode

NOTE: SYSTEM TEST consists of a stationary test and a road test. The SYSTEM TEST mode must be selected from AW4 MENU. See ENTERING AW4 MENU  under RETRIEVING FAULT CODES.
  1. Stationary test monitors transmission system data, current solenoid failures, switch failures, correct TCU application, calibration and operation. Road test checks all valve body solenoids and speed sensor.
  2. On 1991 models, technician will be instructed to place POWER/COMFORT switch first in POWER and then COMFORT position.
  3. On all models, technician will be instructed to place gearshift in each gear position, starting by shifting into 1-2 position. Once transmission is in Park, brake pedal must be depressed to check brake switch.
  4. After brake switch is checked, technician will be instructed to slowly depress throttle. DRB-II will display 7 asterisks (*******) corresponding to throttle position. While depressing accelerator, Throttle Position Sensor (TPS) sweeps through entire range of positions required by the TCU.
  5. A corresponding asterisk will be cleared from DRB-II display as each throttle position is sensed by TCU. Several attempts may be required to clear all asterisks from the display, depending on how fast accelerator is depressed.
  6. After throttle position is checked, technician will be instructed to drive the vehicle. The DRB-II will indicate if a requested action is seen by the TCU. If technician is requested to perform a particular operation, and TCU does not acknowledge the action, press ENTER key to continue testing.
  7. TCU will instruct technician to accelerate vehicle at light throttle to ensure transmission shifts through all gears, indicating proper valve body solenoid operation.
  8. During road test, ensure vehicle can be accelerated slowly and evenly to allow transmission to enter all gear ranges without downshifting or braking. If a fault is sensed, a fault code will be displayed on DRB-II.
NOTE: If TCU senses a fault, control logic activates a specified valve body solenoid to obtain a certain gear depending on failure. Because transmission faults codes are displayed one at a time, multiple fault codes must be identified by retesting transmission.
scientia non olet · About LEMON Manuals