as the malfunction is detected. A stored code indicates there was an
active code present at some time. However, the code currently may not
be present as an active code, although another active code could be.
When a trouble code occurs, the AIR BAG warning light
illuminates for 12 seconds minimum (even if problem existed for less
than 12 seconds). Code is stored, along with time in minutes it was
active, and number of times ignition has been cycled since problem was
detected.
When and if malfunction ceases to exist, an ignition cycle
count will be initiated for that code. If ignition cycle count reaches
100 without a reoccurrence of the same malfunction, DTC is erased and
that ignition cycle counter is reset to zero. If malfunction reoccurs
before count reaches 100, ignition cycle counter will be reset and DTC
will continue to be a stored code.
If a particular code is not active while performing
diagnostic test for that code, code diagnostic test may not locate the
source of the problem. In this case, stored code can only indicate an
area of system to inspect.
If no obvious problems are found, erase stored codes, and
with ignition on, wiggle wiring harness and connectors. Recheck for
codes periodically as you work through system. This procedure may
uncover a difficult problem to locate.
PRETEST INSPECTION & DIAGNOSTIC PROCEDURE
Following precautions and procedures must be followed:
* Always follow air bag service precautions to avoid air bag
deployment and possible personal injury. Refer to procedure
under See SERVICE PRECAUTIONS.
* After component replacement, ensure proper system operation.
See SYSTEM OPERATION CHECK .
* When testing voltage or continuity at ACM, use terminal side
(not wire end) of connector. DO NOT probe wire through
insulation.
* Always check if any TECH SERVICE BULLETINS (TSBs) apply to
vehicle.
* When using diagnostic charts, DO NOT skip any steps in chart
or incorrect diagnosis may result. Always perform
SYSTEM OPERATION CHECK after repairs are made.
* Always use most current DRB diagnostic program cartridge
available to prevent erroneous codes or test results.
* When using diagnostic charts, use DRB voltmeter unless
instructed to use an external voltmeter. Never use a test
light in place of a voltmeter.
* When performing electrical tests, prevent accidental
shorting of terminals. Such shorts can damage fuses or
components and may cause a second code (message) to be
set, making diagnosis of original problem more difficult.
* Vehicle must have a fully-charged battery and functional
charging system.
* Each time a connector is disconnected, inspect it to ensure
it is in good condition. Always focus on circuit being
tested. Dirt, water and corrosion, are most common problems
in connectors.
* Always disconnect DRB after use.
* Always disconnect DRB before charging battery.
USING DRB
1) Refer to DRB user guide for instructions and assistance
with reading trouble codes and other DRB functions. Under normal
operation DRB will display one of only 2 error messages: User-
cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION.
Reconnect negative battery cable. Measure voltage between ground and
terminal No. 6 (Pink/White wire) of instrument cluster connector C1.
See Fig. 1 . If battery voltage is present, reinstall instrument
cluster and go to SELF- DIAGNOSTICS. If battery voltage is not
present, repair open circuit between fuse No. 12 (15-amp) in junction
block and instrument cluster connector C1 and go to next step.
5) Remove and inspect fuse No. 11 (10-amp) in junction block\
.
If fuse is okay, go to next step. If fuse is blown, locate and repair
cause of blown fuse. Install new fuse and recheck system operation.
6) Turn ignition on. Measure voltage between ground and power
side (Dark Blue/White wire) of fuse No. 11 (10-amp) in junction bloc\
k.
If battery voltage is present, go to step 8). If battery voltage is
not present, locate and repair open circuit to fuse No. 11. See WIRING
DIAGRAMS.
7) Turn ignition off and disconnect negative battery cable.
Install instrument cluster. Connect negative battery cable. Turn
ignition on. Set parking brake and observe instrument cluster brake
warning light. If brake warning light is on, go to next step. If brake
warning light is off, go to step 9).
8) Turn ignition off. Turn parking lights on and adjust
instrument panel lights dimmer rheostat to full bright position. If
instrument panel lights are on, go to step 10). If instrument panel
lights are off, repair instrument cluster illumination ground circuit
between instrument cluster connector C2 terminal No. 7 (Black wire)
and ground. See WIRING DIAGRAMS.
9) Turn ignition off and disconnect negative battery cable.
Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL &
INSTALLATION. Connect negative battery cable. Turn ignition on.
Measure voltage between ground and terminal No. 2 (Dark Blue/White
wire) at instrument cluster connector C1. If battery voltage is
present, go to SELF-DIAGNOSTICS. If battery voltage is not present,
repair open circuit between junction block fuse No. 11 and instrument
cluster.
10) Turn ignition off and disconnect negative battery cable.
Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL &
INSTALLATION. Check continuity between ground and terminal No. 4
(Black/Dark Green wire) at instrument cluster connector C1. If
continuity exists, go to SELF-DIAGNOSTICS. If continuity does not
exist, locate and repair open in ground circuit.
SELF-DIAGNOSTICS
1) With ignition off, press and hold trip odometer RESET
button while turning ignition switch to ON position. Continue to hold
RESET button until odometer window displays CHEC (about 10 seconds).
Release RESET button. If problem exists, system will display
Diagnostic Trouble Codes (DTC). See DIAGNOSTIC CODE CHART table. For
repairs of DTCs, see appropriate BODY CONTROL COMPUTER TESTS article.
DIAGNOSTIC TROUBLE (DTC) CODE CHART
\
\
\
\
\
\
\
DTC Description Correction
\b\
\
\
\
\b\
\
\
110 Cluster CPU, RAM Or EEPROM Fault Replace Cluster
\b\
\
\
\
\b\
\
\
900 CCD Bus Inoperative Check CCD Bus Connections At
Cluster; Check Cluster
Fuses; Check CCD Bus Bias;
Check CCD Bus Voltage;
Check CCD Bus Terminations
\b\
\
\
\
\b\
\
\
920 Not Receiving VSS Message From PCM Check PCM Software Level;
PA R ASIT IC L O AD E XPLA N ATIO N & T E ST P R O CED URES
1999 D odge P ic ku p R 1500
GENERAL INFORMATION
Parasitic Load Explanation & Test Procedures
* PLEASE READ THIS FIRST *
This article is provided for general information only. Not
all procedures apply to all makes and models.
GENERAL INFORMATION
The term Parasitic Load refers to electrical devices that
continue to use or draw current after the ignition switch is turned to
OFF position. This small amount of continuous battery draw is
expressed in milliamps (mA). On Ford Motor Co. and General Motors
vehicles produced after 1980, a typical Parasitic Load should be no
more than 50 milliamps (0.050 amps).
Vehicles produced since 1980 have memory devices that draw
current with ignition off for as long as 20 minutes before shutting
down the Parasitic Drain. When Parasitic Load exceeds normal
specifications, the vehicle may exhibit dead battery and no-start
condition.
Follow test procedure for checking Parasitic Loads to
completion. A brief overview of a suggested test procedure is included
along with some typical Parasitic Load specifications. Refer to the
GENERAL MOTORS PARASITIC LOAD TABLE chart.
TESTING FOR PARASITIC LOAD
INTRODUCTION
CAUTION: Always turn ignition off when connecting or disconnecting
battery cables, battery chargers or jumper cables. DO NOT
turn test switch to OFF position (which causes current to run
through ammeter or vehicle electrical system).
NOTE: Memory functions of various accessories must be reset after
the battery is reconnected.
The battery circuit must be opened to connect test switch
(shunt) and ammeter into the circuit. When a battery cable is removed,\
timer circuits within the vehicle computer are interrupted and
immediately begin to discharge. If in doubt about the condition of the
ammeter fuse, test it with an ohmmeter prior to beginning test. An
open fuse will show the same reading (00.00) as no parasitic drain.
Begin test sequence with the meter installed and on the 10-amp scale.
Select lower scale to read parasitic draw.
TEST PROCEDURE USING TEST SWITCH
1) Turn ignition off. Remove negative battery terminal cable.
Install Disconnect Tool (J-38758) test switch male end to negative
battery cable. Turn test switch knob to OFF position (current through
meter). Install negative battery cable to the female end of test
switch.
2) Turn test switch knob to ON position (current through
switch). Road test vehicle with vehicle accessories on (radio, air
conditioner, etc.). After road test, turn ignition switch to LOCKED
position and remove key. Connect ammeter terminals to test switch