Reading and Clearing Diagnostic Trouble Codes
THE DRBIIThe DRBII must be used to diagnose problems in the A-604 system. The tester is connected to the Chrysler C2D Bus connector located under the dash. It is important to remember not to use the engine diagnostic connector located under the hood.
The following is a brief description of DRBII capabilities:
Diagnostic Test - This capability allows the technician to read and erase fault codes stored in the A-604 Controller's memory.
Circuit Actuation Test - This capability allows the technician to turn on and off (toggle) certain A-604 components. This ability allows easier and more accurate testing of those circuits.
Switch Test - This capability allows the technician to view various changing switch positions as seen by the controller.
Sensor Test - This capability allows the technician to monitor A-604 sensors on the DRBII display.
Engine Running Test - This capability allows the technician to see various sensor signals received by the A-604 controller. Also, certain A604 components may be actuated by the technician during this mode.
There are different manufacturers of diagnostic read-out boxes which can be used on Chrysler cars. It is important to remember that A-604 diagnostics are available only through equipment that can communicate on Chrysler's Bus. This diagnostic test procedure has been designed specifically to be used with Chrysler's DRBII.
Connecting The DRBII To The Vehicle
The DRBII is connected to the vehicle through the bus connector located under the dash. This blue connector must not be confused with the familiar SCI connector found under the hood which is used to access the engine controller (SMEC).
A special adapter cable (supplied with the DRBII) is needed to interface with the bus connector. No other power supply or connection is needed.
Operation Of The DRBII
Once connected to the bus connector, the ignition switch is turned to the run position. A Chrysler logo and system level number will be displayed: Move to the "Select System Transmission", and press Yes. Select the A-604.
After a short pause and a successful Bus Test, the DRBII will automatically display:
SELECT TEST
SHIFT LEVER STATUS
A6O4 TRANSAXLE
PRESS F1, F2 FOR MORE
From this screen you can drop into a display that quickly tests the accuracy of the circuits that tell the transaxle controller what position the shift lever (manual valve) is in.
NOTE: It is extremely important that accurate shifter data be available to the A604 controller. The accuracy of any fault code found in memory is doubtful unless this test passes without fail.
Once at the "SELECT TEST" level, moving to the right (F2) or left (F1) will make the following tests available:
NOTE: See the "DRBII Functional Flow Diagram" at the front of this book.
- SHIFT LEVER STATUS (present position)
- SHIFT LEVER TEST A closer look at shifter positions (to be used if the shift lever status test fails)
- DISPLAY FAULT CODES View any fault codes in memory.
- CLEAR FAULT CODES Drop into this area to erase stored fault codes.
- EATX MISC. INFO View module information and clutch volumes here.
- PRESSURE TEST Command various hydraulic circuits via electronics.
- CLUTCH TEST Evaluate clutch assemblies for slipping.
- RPM DISPLAY Read engine, turbine and output speed simultaneously.
- SENSOR TEST The output of various sensors and switches can be viewed here. PRESSURE SWITCH TEST View internal pressure switch states here.
The DRBII Limp-in Indicator Lamp
Once the DRBII is in the AUTOMATIC TRANSAXLE section, it will constantly monitor the A-604 Controller to see if the system is in limp-in. If transaxle limp-in occurs, the DRBII will turn on its red LED indicator.
The following fault codes will cause the transaxle to go into limp-in:
11 13 14 15 16 17 18 20 21 22 23 24 25 26 27 31 32 33 39 41 42 43 44.
The following fault codes will not cause the transaxle to go into limp-in:
12 19 28 29 37 38 46.
HOW TO USE THE DRBII VOLT/OHMMETER
The Volt/Ohmmeter function can only be turned on at the Select Test level or below.
NOTE: The Volt/Ohmmeter function will not operate in the Display Fault Code or the Clear Fault Code section.
Making Voltage Measurements
1. Connect the Volt/Ohmmeter test lead to the DRBII.
2. Press the Volt/Ohm key on the keypad once.
NOTE: The DRBII will remember what Test Mode you are in while in the Volt/Ohmmeter function.
3. Touch the test probe to the connector or wire to be measured and read the results on the DRBII display.
4. After all measurements have been made, press the Volt/Ohm key twice to return to the Test Mode you left before you entered the Volt/Ohmmeter function.
Making Ohmmeter Measurements
1. Connect the red Volt/Ohmmeter test lead to the DRBII.
2. Press the Volt/Ohm key on the keypad twice.
NOTE: Because of the way the DRBII Ohmmeter is configured (one lead), you will only be able to test wires or components to ground.
3. Touch the red test probe to the wire or component you wish to test and read the resistance to ground on the DRBII display.
4. After all measurements have been made, press the Volt/Ohm key once to return to the Test Mode you were in before you entered the Volt/Ohmmeter function.