Chrysler PT Cruiser 2001 Service Manual Supplement page 1964

4.3 WARNING
4.3.1 VEHICLE DAMAGE WARNINGS
Before disconnecting any control module, make
sure the ignition is ''off ''. Failure to do so could
damage the module.
When testing voltage or continuity at any control
module, use the terminal side (not the wire end) of
the connector. Do not probe a wire through the
insulation, this will damage it and eventually cause
it to fail because of corrosion.
Be careful when performing electrical tests so as
to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, a
second code could be set, making diagnosis of the
original problem more difficult.
4.3.2 ROAD TESTING A COMPLAINT
VEHICLE
Some complaints will require a test drive as part
of the repair verification procedure. The purpose of
the test drive is to try to duplicate the diagnostic
code or symptom condition.
CAUTION: BEFORE
VEHICLE, BE
COMPONENTS ARE
DURING THE TEST DRIVE, DO NOT TRY TO
READ THE DRBIII
MOTION. DO NOT HANG THE DRBIII FROM
THE REAR VIEW MIRROR OR OPERATE IT
YOURSELF. HAVE
AVAILABLE TO OPERATE THE DRBIII .
4.4 DIAGNOSIS
1. Your diagnostic test procedure must begin with a
thorough visual inspection of the ABS system for
damaged components or disconnected connec-
tors. The brake lamps must be operational, and
if they are not, repair them prior to continuing.
2. Connect the DRBIII to the data link connector,
located under the dash to the left of the steering
column. If the DRBIII does not power up, check
the power and ground supplies to the connector.
3. Select ''Antilock Brakes''. Turn the ignition on. If
the DRBIII displays ''No Response'', perform
the proper test.
4. Read and record all ABS diagnostic trouble
codes. If the ''CAB Power Feed Circuit'' diagnos-
tic trouble code is present, it must be repaired
prior to addressing any other DTC's. If any
additional codes are present, proceed to the
appropriate test.
ROAD TESTING
SURE THAT ALL
REASSEMBLED.
SCREEN WHILE IN
AN ASSISTANT
GENERAL INFORMATION
5. If there are no diagnostic trouble codes present,
select ''Inputs/Outputs'' and read the brake
switch input as you press and release the brake
pedal. If the display does not match the state of
the pedal, perform the proper test. Read the
''Traction Control Switch'' status, the switch
should read ''CLOSED''. If the status is not
correct, perform the proper test. If a problem
with the amber ''ABS'' warning indicator exists,
refer to the proper test.
6. If no other problems are found, it will be neces-
sary to road test the vehicle. THE DRBIII
MUST NOT BE CONNECTED TO THE
DATA LINK CONNECTOR WHEN ROAD
TESTING FOR PROPER ANTILOCK OP-
ERATION. THE SYSTEM IS DISABLED
WHILE IN DIAGNOSTIC MODE. Perform
several antilock stops from above 50 Km/h (30
mph) and then repeat steps 2, 3, and 4. If any
diagnostic trouble codes are present, proceed to
the appropriate test.
7. The following conditions should be considered
''NORMAL'' operation, and no repairs should be
attempted to correct them.
– Brake pedal feedback during an ABS stop
(clicking, vibrating)
A
– Clicking, groaning or buzzing at 20 Km/h (12
mph) (drive off self test)
– Groaning noise during an ABS stop
– Slight brake pedal drop and pop noise when
ignition is initially turned on
– Brake pedal ratcheting down at the end of an
ABS stop.
8. If the complaint is ABS ''cycling'' at the end of a
stop at low speeds, it may be caused by a
marginal wheel speed sensor signal. The sensor
air gap, tone wheel condition, and/or brakes
hanging up are possible causes of this condition.
9. After a road test and no problems were found,
refer to any Technical Service Bulletins that may
apply.
5.0 REQUIRED TOOLS AND
EQUIPMENT
DRBIII (diagnostic read-out box)
jumper wires
ohmmeter
voltmeter
test light
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