Dodge RAM TRUCK 1500 1995 Service Manual page 389

8D -16 IGNITION SYSTEMS
COIL " \
CONNECTOR
J9314-160
Fig. 21 Coil Harness Connector—5*91 V-8 HDC-Gas
Engine
voltmeter to a good ground. Determine that sufficient
battery voltage (12.4 volts) is present for the starting
and ignition systems.
(4) Crank the engine for 5 seconds while monitor­
ing the voltage at the coil positive terminal:
• If the voltage remains at zero during the entire pe­
riod of cranking, refer to On-Board Diagnostics in
Group 14, Fuel Systems. Check the powertrain con­
trol module and auto shutdown relay.
• If voltage is at or near battery voltage and drops
to zero after 1-2 seconds of cranking, check the pow­
ertrain control module circuit. Refer to On-Board Di­
agnostics in Group 14, Fuel Systems.
© If voltage remains at or near battery voltage dur­
ing the entire 5 seconds, turn the key off. Remove
the 60-way connector (Fig. 22) from the powertrain
control module (PCM). Check 60-way connector for
any spread terminals.
CONNECTOR
TERMINAL SIDE
S H O W N
J908D-42
Fig. 22 PCM 60-Way Connector
(5) Remove test lead from the coil positive termi­
nal. Connect an 18 gauge jumper wire between the
battery positive terminal and the coil positive termi­
nal.
(6) Make the special jumper shown in figure 23.
Using the jumper, momentarily ground terminal-19
of the 60-way connector. A spark should be generated
at the coil cable when the ground is removed.
CAPACITOR
GROUND
THIS
CLIP
CONNECT THIS
CLIP TO COIL
.33 MF
ALLIGATOR CLIP
- 7 - r . 7 ALLIGATOR
- g & Z ' ^ CLIP
/MOMENTARILY
- J GROUND THIS
CLIP TO COII
NEGATIVE
RB1003
Fig. 23 Special Jumper Ground-to-Coil Negative
Terminal
(7) If spark is generated, replace the powertrain
control module (PCM).
(8) If spark is not seen, use the special jumper to
ground the coil negative terminal directly.
(9) If spark is produced, repair wiring harness for
an open condition.
(10) If spark is not produced, replace the ignition
coil.
IGNITION TIMING
Base (initial) ignition timing is NOT adjust­
able on any engine. On a 3.9L V-6 or a 5.2/5.9L
V-8 engine, do not attempt to adjust ignition
timing by rotating the distributor. The rota­
tional position of the distributor is determining
fuel synchronization only.
All ignition timing functions are controlled by the
powertrain control module (PCM). Refer to On-Board
Diagnostics in the Multi-Port Fuel Injection—Gen­
eral Diagnosis section of Group 14, Fuel Systems for
more information. Also refer to the appropriate Pow­
ertrain Diagnostics Procedures service manual for op­
eration of the DRB Scan Tool.
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
TEST
For an operational description, diagnosis and re­
moval and installation procedures, refer to Group 14,
Fuel System.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
TEST
To perform a complete test of MAP sensor and its
circuitry, refer to DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual. To test
the MAP sensor only, refer to MAP Sensor in Group
14, Fuel System.
POWERTillN CONTiOL MODULE (PCM)
The powertrain control module (PCM) is located in
the right-rear side of the engine compartment (Fig.
24). The PCM was formerly referred to as the SBEC
or engine controller.
The ignition system is controlled by the PCM.
For removal and installation of this component, re-