Diagnosis And Testing; Checking For Diagnostic Codes; Road Test - Chrysler Stratus RHD 1997 Interactive Electronic Service Manual

8H - 4 VEHICLE SPEED CONTROL SYSTEM
DESCRIPTION AND OPERATION (Continued)
the PCM determines when a deceleration condition
occurs.

DIAGNOSIS AND TESTING

ROAD TEST

Perform a vehicle road test to verify reports of
speed control system malfunction. The road test
should include attention to the speedometer. Speed-
ometer operation should be smooth and without flut-
ter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to Group 8E,
Instrument Panel and Gauges for speedometer diag-
nosis.
If a road test verifies an inoperative system, and
the speedometer operates properly, check for:
• A Diagnostic Trouble Code (DTC). If a flash
lamp code 15, 34 or 77 exists at the Check Engine
Lamp (MIL), conduct tests per the Powertrain Diag-
nostic Procedures service manual.
• A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
• Loose or corroded electrical connections at the
servo. Corrosion should be removed from electrical
terminals and a light coating of Mopar MultiPurpose
Grease, or equivalent, applied.
• Loose or leaking vacuum hoses or connections.
• Secure attachment at both ends of the speed
control servo cable.
• Smooth operation of throttle linkage and throttle
body air valve.
• Failed speed control servo. Do the servo vacuum
test.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals or seals. If
these components are damaged, intermittent or
complete system failure may occur.

CHECKING FOR DIAGNOSTIC CODES

When trying to verify a speed control system elec-
tronic malfunction: Connect a DRB scan tool if avail-
able to the data link connector (Fig. 3). The connector
is located at left side of the steering column, and at
lower edge of the panel.
If a scan tool is not available, use the following
procedure:
(1) With key inserted in ignition switch, cycle
switch to ON position three times. On third cycle,
leave switch in ON position.
HOOD RELEASE
(2) After switch has been cycled three times,
observe MALFUNCTION INDICATOR LAMP (check
engine) indicator on instrument cluster. If a diagnos-
tic code is present, indicator will flash (blink) in a
series which will show which diagnostic code is the
problem. Example: A series of three flashes in rapid
succession, a slight pause, then four flashes in rapid
succession would indicate diagnostic code 34.
(3) A speed control malfunction may occur without
either diagnostic code being indicated. If no diagnos-
tic code appears or diagnostic code 15 or 34 is
observed, refer to the appropriate flow chart.
Fig. 3 Data Link Connector Location
Refer to Group 25, for further information and use-
age of the DRB scan tool and a more complete list of
Diagnostic Trouble Code.
SPEED CONTROL ACCELERATES OR TAPS UP
BY ITSELF
Check for diagnostic trouble codes. If code 15 refer
to the Powertrain Diagnostic Manual, if code 34 per-
form the following test:
(1) Conduct the speed control switch test on the
RESUME/ACCEL switch.
(2) If it fails, replace switch.
(3) If it passes, disconnect the 4 way connector at
servo. Test continuity of pin 1 to ground to test for
intermittent short. Wiggle wires while preforming
test.
(4) If continuity to ground, repair wiring.
(5) If no continuity to ground, replace PCM.
SPEED CONTROL SLOWS DOWN BY ITSELF
Test vehicle speed sensor, refer to group 8E. If sen-
sor fails replace sensor, if it passes perform the fol-
lowing test:
(1) Perform the speed control switch test on the
SET/COAST switch, if it fails replace switch.
(2) If the switch passes, conduct the vacuum sup-
ply test.
DIAGNOSTIC DRIVER'S KICK PANEL NECTOR SIDE CON-
JA