Dodge Dakota (R1). Manual - part 354

trolled and vacuum operated. Electronic control of
the speed control system is integrated into the Pow-
ertrain Control Module (PCM). The controls consist
of

two

steering

wheel

mounted

switches.

The

switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.

The system is designed to operate at speeds above

30 mph (50 km/h).

WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.

OPERATION

When speed control is selected by depressing the

ON switch, the PCM allows a set speed to be stored
in PCM RAM for speed control. To store a set speed,
depress the SET switch while the vehicle is moving
at a speed between 35 and 85 mph. In order for the
speed control to engage, the brakes cannot be
applied, nor can the gear selector be indicating the
transmission is in Park or Neutral.

The speed control can be disengaged manually by:
• Stepping on the brake pedal

• Depressing the OFF switch

• Depressing the CANCEL switch.

• Depressing the clutch pedal (if equipped).

NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the PCM.

For added safety, the speed control system is pro-

grammed to disengage for any of the following condi-
tions:

• An indication of Park or Neutral

• A rapid increase rpm (indicates that the clutch

has been disengaged)

• Excessive engine rpm (indicates that the trans-

mission may be in a low gear)

• The speed signal increases at a rate of 10 mph

per second (indicates that the coefficient of friction
between the road surface and tires is extremely low)

• The speed signal decreases at a rate of 10 mph

per second (indicates that the vehicle may have
decelerated at an extremely high rate)

Once the speed control has been disengaged,

depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the PCM.

While the speed control is engaged, the driver can

increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
PCM when the RES/ACCEL is released. The PCM
also has a

9tap-up9 feature in which vehicle speed

increases at a rate of approximately 2 mph for each
momentary switch activation of the RES/ACCEL
switch.

SPEED CONTROL

8P - 1

A “tap down” feature is used to decelerate without

disengaging the speed control system. To decelerate
from an existing recorded target speed, momentarily
depress the COAST switch. For each switch activa-
tion, speed will be lowered approximately 1 mph.

OVERSHOOT/UNDERSHOOT

If the vehicle operator repeatedly presses and

releases the SET button with their foot off of the
accelerator (referred to as a “lift foot set”), the vehicle
may accelerate and exceed the desired set speed by
up to 5 mph (8 km/h). It may also decelerate to less
than the desired set speed, before finally achieving
the desired set speed.

The Speed Control System has an adaptive strat-

egy that compensates for vehicle-to-vehicle variations
in speed control cable lengths. When the speed con-
trol is set with the vehicle operators foot off of the
accelerator pedal, the speed control thinks there is
excessive speed control cable slack and adapts
accordingly. If the “lift foot sets” are continually used,
a speed control overshoot/undershoot condition will
develop.

To “unlearn” the overshoot/undershoot condition,

the vehicle operator has to press and release the set
button while maintaining the desired set speed using
the accelerator pedal (not decelerating or accelerat-
ing), and then turning the cruise control switch to
the OFF position (or press the CANCEL button if
equipped) after waiting 10 seconds. This procedure
must be performed approximately 10–15 times to
completely unlearn the overshoot/undershoot condi-
tion.

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, Instru-
ment Panel and Gauges for speedometer diagnosis.

If a road test verifies a system problem and the

speedometer operates properly, check for:

• A Diagnostic Trouble Code (DTC). If a DTC

exists, conduct tests per the Powertrain Diagnostic
Procedures service manual.

• A misadjusted brake (stop) lamp switch. This

could also cause an intermittent problem.

• Loose, damaged or corroded electrical connec-

tions at the servo. Corrosion should be removed from
electrical terminals and a light coating of Mopar
MultiPurpose Grease, or equivalent, applied.

• Leaking vacuum reservoir.

• Loose or leaking vacuum hoses or connections.

• Defective one-way vacuum check valve.

• Secure attachment of both ends of the speed con-

trol 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.

SPECIFICATIONS

TORQUE - SPEED CONTROL

DESCRIPTION

N-m

Ft. Lbs.

In. Lbs.

Servo Mounting Bracket-to-Servo Nuts

8.5

Servo Mounting Bracket-to-Body Nuts

7-10

63-94

Switch Module Mounting Screws

1.5

Vacuum Reservoir Mounting Bolts

2.2

8P - 2

SPEED CONTROL

SPEED CONTROL (Continued)

CABLE

DESCRIPTION

The speed control servo cable is connected between

the speed control vacuum servo diaphragm and the
throttle body control linkage.

OPERATION

This cable causes the throttle control linkage to

open or close the throttle valve in response to move-
ment of the vacuum servo diaphragm.

REMOVAL - EXCEPT 4.7L

(1) Disconnect negative battery cable at battery.
(2) Using finger pressure only, remove speed con-

trol cable connector at throttle body bellcrank by
pushing connector off the bellcrank pin (Fig. 1) or
(Fig. 2). DO NOT try to pull connector off per-
pendicular to the bellcrank pin. Connector will
be broken.

(3) 2.5L Engine: Remove cable from cable guide at

top of valve cover.

(4) Squeeze 2 tabs on sides of speed control cable

at throttle body mounting bracket (locking plate) and
push out of bracket.

(5) Remove servo cable from servo. Refer to Speed

Control Servo Removal/Installation.

REMOVAL - 4.7L

(1) Disconnect negative battery cable at battery.
(2) Remove air box housing from throttle body.
The accelerator cable must be partially removed to

gain access to speed control cable.

(3) Using finger pressure only, disconnect accelera-

tor cable connector at throttle body bellcrank pin by
pushing connector off bellcrank pin towards front of
vehicle (Fig. 3). DO NOT try to pull connector off
perpendicular to the bellcrank pin. Connector
will be broken.

(4) Lift accelerator cable from top of cable cam

(Fig. 3).

(5) Press tab (Fig. 4) to release plastic cable mount

from bracket. Press on tab only enough to
release cable from bracket. If tab is pressed too
much, it will be broken. Slide plastic mount (Fig.
4) towards passenger side of vehicle to remove cable
from bracket.

(6) Using finger pressure only, disconnect speed

control cable connector at throttle body bellcrank pin
by pushing connector off bellcrank pin towards front
of vehicle (Fig. 3). DO NOT try to pull connector
off perpendicular to the bellcrank pin. Connec-
tor will be broken.

(7) Slide speed control cable plastic mount towards

passenger side of vehicle to remove cable from
bracket (Fig. 5).

Fig. 1 Cable Connection at Throttle Body—2.5L

Engine

1 - BELLCRANK
2 - CABLE CONNECTOR
3 - SPEED CONTROL CABLE

Fig. 2 Cable Connection at Throttle Body—3.9L/

5.2L/5.9L Engines

1 - VEHICLE SPEED CONTROL CABLE

SPEED CONTROL

8P - 3

Content .. 352 353 354 355 ..