Oxygen sensor heater relays. Throttle body-3.9/5.2/5.9L engines

Oxygen sensor heater relays

The oxygen sensor heater relays are located in the Power Distribution Center (PDC) (Fig. 17). Refer to label on PDC cover for relay location.

REMOVAL

(1) Remove PDC cover.

(2) Remove relay from PDC.

(3) Check condition of relay terminals and PDC connector terminals for damage or corrosion. Repair if necessary before installing relay.

(4) Check for pin height (pin height should be the same for all terminals within the PDC connector).

Repair if necessary before installing relay.

INSTALLATION

(1) Install relay to PDC.

(2) Install cover to PDC.

Throttle body-3.9/5.2/5.9L engines

A (factory adjusted) set screw is used to mechanically limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the powertrain control module (PCM).

REMOVAL

(1) Remove the air duct at throttle body.

(2) Disconnect throttle body electrical connectors at MAP sensor, IAC motor and TPS (Fig. 18).

(3) Remove vacuum line at throttle body.

(4) Remove all control cables from throttle body (lever) arm. Refer to the Accelerator Pedal and Throttle Cable section of this group for additional information.

(5) Remove four throttle body mounting bolts (Fig.

19).

(6) Remove throttle body from intake manifold.

(7) Discard old throttle body-to-intake manifold gasket.

INSTALLATION

(1) Clean the mating surfaces of the throttle body and the intake manifold.

(2) Install new throttle body-to-intake manifold gasket.

(3) Install throttle body to intake manifold.

(4) Install four mounting bolts. Tighten bolts to 23 N*m (200 in. lbs.) torque.

(5) Install control cables.

(6) Install vacuum line to throttle body.

(7) Install electrical connectors.

Fig. 18 Sensor Electrical Connectors-3.9/5.2/5.9L Engines-Typical

1 - MAP SENSOR

2 - IDLE AIR CONTROL MOTOR

3 - THROTTLE POSITION SENSOR

Fig. 19 Throttle Body Mounting Bolts-3.9/5.2/5.9L Engines-Typical

1 - THROTTLE BODY MOUNTING BOLTS (4)

2 - THROTTLE BODY

(8) Install air duct at throttle body.