Dodge ram truck 3500 1996 Service Manual page 1280

1 4 - 4 6 FUEL SYSTEM B R
DIAGNOSIS AND TESTING (Continued)
DOWN STREAM , UP STREAM
OXYGEN OXYGEN
SENSOR SENSOR
80570e21
Fig. 43 Upstream/Downstream Oxygen
Sensors—3.9U5.2U5.9L LDC Engines
(22) On 5.9L HDC engines, verify that both the
left and right oxygen sensor wire connectors are
firmly connected to the sensors. Inspect sensors and
connectors for damage (Fig. 44).
Fig. 44 Left/Right Oxygen Sensors—5.9L HDC Engines
(23) Inspect for pinched or leaking fuel tubes.
Inspect for pinched, cracked or leaking fuel hoses.
(24) Inspect for exhaust system restrictions such as
pinched exhaust pipes, collapsed muffler or plugged cat­
alytic convertor.
(25) I f equipped with automatic transmission, ver­
ify that electrical harness is firmly connected to park/
neutral switch. Refer to Automatic Transmission
section of Group 21.
(26) Verify that the electrical harness connector is
firmly connected to the vehicle speed sensor (Fig. 45).
(27) Verify that fuel pump/gauge sender unit wire
connector is firmly connected to harness connector.
(28) Inspect fuel hoses at fuel pump/gauge sender
unit for cracks or leaks.
(29) Inspect transmission torque convertor housing
(automatic transmission) or clutch housing (manual
SENSOR
ELECTRICAL
CONNECTOR
J9414-60
Fig. 45 Vehicle Speed Sensor—Typical
transmission) for damage to timing ring on drive
plate/flywheel.
(30) Verify that battery cable and solenoid feed
wire connections to the starter solenoid are tight and
clean. Inspect for chaffed wires or wires rubbing up
against other components.
USUAL INSPECTION—8 J L ENGINE
A visual inspection for loose, disconnected or incor­
rectly routed wires and hoses should be made. This
should be done before attempting to diagnose or service
the fuel injection system. A visual check will help spot
these faults and save unnecessary test and diagnostic
time. A thorough visual inspection will include the follow­
ing checks:
(1) Verify that the three 32-way electrical connec­
tors are fully inserted into the connector of the pow­
ertrain control module (PCM) (Fig. 46).
Fig. 46 Powertrain Control Module (PCM)