
When diagnosing a chassis system problem, it is
important to follow approved procedures where
applicable. These procedures can be found in this
General Information Section or in the service man-
ual procedures. Following these procedures is very
important to safety of individuals performing diag-
nostic tests.
4.2.2 VEHICLE PREPARATION FOR
TESTING
Make sure the vehicle being tested has a fully
charged battery. If it does not, false diagnostic codes
or error messages may occur.
4.2.3 SERVICING SUB-ASSEMBLIES
Some components of the chassis system are in-
tended to be serviced as an assembly only. Attempt-
ing to remove or repair certain system sub-
components may result in personal injury and/or
improper system operation. Only those components
with approved repair and installation procedures in
the service manual should be serviced.
4.2.4 DRBIIITSAFETY INFORMATION
WARNING: EXCEEDING THE LIMITS OF THE
DRBIIITMULTIMETER IS DANGEROUS. IT
CAN EXPOSE YOU TO SERIOUS OR
POSSIBLY FATAL INJURY. CAREFULLY
READ AND UNDERSTAND THE CAUTIONS
AND THE SPECIFICATION LIMITS.
²Follow the vehicle manufacturer 's service speci-
fications at all times.
²Do not use the DRBIIItif it has been damaged.
²Do not use the test leads if the insulation is
damaged or if metal is exposed.
²To avoid electrical shock, do not touch the test
leads, tips, or the circuit being tested.
²Choose the proper range and functions for the
measurement. Do not try voltage or current mea-
surement that may exceed the rated capacity.
²Do not exceed the limits shown in the table below:
FUNCTION INPUT LIMIT
Volts 0 - 500 peak volts AC
0 - 500 volts DC
Ohms (resistance)* 0 -1.12 megohms
Frequency Measured
Frequency Generated0-10kHz
Temperature -58 - 1100ÉF
-50 - 600ÉC* Ohms cannot be measured if voltage is present.
Ohms can be measured only in a non-powered
circuit.
²Voltage between any terminal and ground must
not exceed 500v DC or 500v peak AC.
²Use caution when measuring voltage above 25v
DC or 25v AC.
²Use the low current shunt to measure circuits up
to 10A. Use the high current clamp to measure
circuits exceeding 10A.
²When testing for the presence of voltage or cur-
rent, make sure the meter is functioning cor-
rectly. Take a reading of a known voltage or
current before accepting a zero reading.
²When measuring current, connect the meter in
series with the load.
²Disconnect the live test lead before disconnecting
the common test lead.
²When using the meter function, keep the
DRBIIItaway from spark plug or coil wires to
avoid measuring error from outside interference.
4.3 WARNINGS
4.3.1 VEHICLE DAMAGE WARNINGS
Before disconnecting any control module, make
sure the ignition is ªoffº. Failure to do so could
damage the module.
When testing voltage or continuity at any control
module, use the terminal side (not the wire end) of
the connector. Do not probe a wire through the
insulation; this will damage it and eventually cause
it to fail because of corrosion. Be careful when
performing electrical tests so as to prevent acciden-
tal shorting of terminals. Such mistakes can dam-
age fuses or components. Also, a second code could
be set, making diagnosis of the original problem
more difficult.
4.3.2 ROAD TESTING A COMPLAINT
VEHICLE
Some complaints will require a test drive as part
of the repair verification procedure. The purpose of
the test drive is to try to duplicate the diagnostic
code or symptom condition.
29
GENERAL INFORMATION

WARNING: BEFORE ROAD TESTING A
VEHICLE, BE SURE THAT ALL
COMPONENTS ARE REASSEMBLED.
DURING THE TEST DRIVE, DO NOT TRY TO
READ THE DRBIIITSCREEN WHILE IN
MOTION. DO NOT HANG THE DRBIIITFROM
THE REAR VIEW MIRROR OR OPERATE IT
YOURSELF. HAVE AN ASSISTANT
AVAILABLE TO OPERATE THE DRBIIIT.
5.0 REQUIRED TOOLS AND
EQUIPMENT
DRBIIIt(diagnostic read-out box)
Jumper wires
Ohmmeter
Voltmeter
Sentry Key Tester
Test Light
8310 Airbag System Load Tool
8443 SRS Airbag System Load Tool
Diagnostic Junction Port Tester 8339
6.0 GLOSSARY OF TERMS
ABSantilock brake system
ACMairbag control module
AECMairbag electronic control module
(ACM)
ASDMairbag system diagnostic module
(ACM)
AT Cautomatic temperature control
BCMbody control module
CABcontroller antilock brake
CMTCcompass/mini-trip computer
CPAconnector positive assurance
DABdriver airbag
DCHAdiesel cabin heater assist
(cabin heater)
DLCdata link connector
DTCdiagnostic trouble code
DRdriver
EBLelectric back lite (rear window de-
fogger)ECMEngine control module
EVICelectronic vehicle information center
FCMfront control module
GCCGulf Coast Countries
HVACheater ventilation, air conditioning
IPMintelligent power module
LDUlower drive unit
LHDLeft Hand Drive
MICmechanical instrument cluster
MTCmanual temperature control
MSMMmemory seat/mirror module
OBDon board diagnostics
ODOodometer
ORCoccupant restraint controller
PA Bpassenger airbag
PASSpassenger
PCIProgrammable Communication In-
terface (vehicle communication bus)
PCMpowertrain control module
PDCpower distribution center
PLGpower liftgate
PLGMpower liftgate module
PSDpower sliding door
PSDMpower sliding door module
PWMpulse width modulated
RHDRight Hand Drive
RKEremote keyless entry
SABseat airbag
SBTseat belt tensioner
SIACMside impact airbag control module
SKIMsentry key immobilizer module
SKISsentry key immobilizer system
SQUIBalso called initiator (located inside
airbag)
SRSsupplemental restraint system
TCMtransmission control module
VFDvacuum fluorescent display
VTSSvehicle theft security system
30
GENERAL INFORMATION

TEST ACTION APPLICABILITY
1 Ensure that the battery is fully charged.
WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
WARNING: IF THE OCCUPANT RESTRAINT CONTROLLER IS DROPPED
AT ANY TIME, IT MUST BE REPLACED.
Disconnect the Occupant Restraint Controller Connector.
NOTE: Check connectors - Clean and repair as necessary.
WARNING: TURN IGNITION ON, THEN RECONNECT THE BATTERY.
With the DRBIIIt, read the active FCM DTCs.
Turn the ignition off.
With the DRBIIIt, read the active FCM DTCs.
NOTE: The ORC RUN ONLY DRIVER OPEN code may not set until the
ignition key is turned off.
Select the active FCM DTC that was displayed on the DRB.All
1. ORC RUN ONLY DRIVER OPEN
Go To 2
2. ORC RUN ONLY DRIVER OVER VOLTAGE
Go To 5
3. ORC RUN ONLY SHORT TO GROUND
Go To 6
4. ORC RUN ONLY DRIVER OVER CURRENT
Go To 6
5. ORC RUN ONLY DRIVER OVER TEMP
Go To 6
6. None of the above.
Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
2WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
WARNING: IF THE OCCUPANT RESTRAINT CONTROLLER IS DROPPED
AT ANY TIME, IT MUST BE REPLACED.
Disconnect the Occupant Restraint Controller.
TURN THE IGNITION ON, THEN RECONNECT THE BATTERY.
Connect a test light to ground and the ORC Run Only Driver circuit at the Occupant
Restraint Controller connector.
Cycle the ignition switch from ON to OFF.
With the DRBIIIt, read the active FCM DTCs.
Does the DRB show an active ORC RUN ONLY DRIVER OPEN code?All
Ye s®Go To 3
No®Replace the Occupant Restraint Controller in accordance with
Service Instructions. WARNING: make sure the battery is discon-
nected and wait 2 minutes before proceeding.
Perform AIRBAG VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
34
AIRBAG
FCM, ORC RUN ONLY DRIVER OPEN - ACTIVE ÐContinued

TEST ACTION APPLICABILITY
3 Disconnect the Front Control Module.
NOTE: Check connectors - Clean and repair as necessary.
Measure the resistance of the ORC Run Only Driver circuit between the Front
Control Module connector and the Occupant Restraint Controller connector.
Is the resistance below 1.0 ohms ?All
Ye s®Replace the Front Control Module.
Perform AIRBAG VERIFICATION TEST - VER 1.
No®Go To 4
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
4 Gain access to the connectors on the bottom of the IPM.
Disconnect the IPM C7 connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the ORC Run Only Driver circuit between the IPM C7
connector and the Occupant Restraint Controller connector.
Is the resistance below 1.0 ohms ?All
Ye s®Replace the IPM.
Perform AIRBAG VERIFICATION TEST - VER 1.
No®Repair the open ORC Run Only Driver circuit.
Perform AIRBAG VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
5 Measure the battery voltage.
Is the voltage above 30.0 volts?All
Ye s®Refer to Charging Category for the P1594 Charging System Too
High symptom.
Perform AIRBAG VERIFICATION TEST - VER 1.
No®Replace the Front Control Module.
Perform AIRBAG VERIFICATION TEST - VER 1.
6WARNING: TURN IGNITION OFF, DISCONNECT THE BATTERY AND WAIT
TWO MINUTES BEFORE PROCEEDING.
Disconnect Occupant Restraints Controller.
NOTE: Check connectors - Clean and repair as necessary.
Measure the resistance of the ORC Run Only Driver circuit between the Front
Control Module connector and ground.
Is the resistance below 500.0 Kohms?All
Ye s®Go To 7
No®Replace the Front Control Module.
Perform AIRBAG VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
35
AIRBAG
FCM, ORC RUN ONLY DRIVER OPEN - ACTIVE ÐContinued

TEST ACTION APPLICABILITY
1 Ensure that the battery is fully charged.
WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
WARNING: IF THE OCCUPANT RESTRAINT CONTROLLER IS DROPPED
AT ANY TIME, IT MUST BE REPLACED.
Disconnect the Occupant Restraint Controller Connector.
NOTE: Check connectors - Clean and repair as necessary.
WARNING: TURN IGNITION ON, THEN RECONNECT THE BATTERY.
With the DRBIIIt, read the active FCM DTCs.
Turn the ignition off.
With the DRBIIIt, read the active FCM DTCs.
NOTE: The ORC RUN-START DRIVER OPEN code may not set until the
ignition key is turned off.
Select the active FCM DTC displayed on the DRB.All
1. ORC RUN-START DRIVER OPEN
Go To 2
2. ORC RUN-START DRIVER OVER VOLTAGE
Go To 5
3. ORC RUN-START SHORT TO GROUND
Go To 6
4. ORC RUN-START DRIVER OVER CURRENT
Go To 6
5. ORC RUN-START DRIVER OVER TEMP
Go To 6
6. None of the above.
Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
2WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
WARNING: IF THE OCCUPANT RESTRAINT CONTROLLER IS DROPPED
AT ANY TIME, IT MUST BE REPLACED.
Disconnect the Occupant Restraint Controller.
TURN THE IGNITION ON, THEN RECONNECT THE BATTERY.
Connect a test light to ground and the ORC Run-Start Driver circuit at the ORC
connector.
Cycle the ignition switch from ON to OFF.
With the DRBIIIt, read the active FCM DTCs.
Does the DRB show an active ORC RUN-START DRIVER OPEN code?All
Ye s®Go To 3
No®Replace the Occupant Restraint Controller in accordance with
Service Instructions. WARNING: make sure the battery is discon-
nected and wait 2 minutes before proceeding.
Perform AIRBAG VERIFICATION TEST - VER 1.
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
43
AIRBAG
FCM, ORC RUN-START DRIVER OPEN - ACTIVE ÐContinued

TEST ACTION APPLICABILITY
1 Ensure that the battery is fully charged.
Turn the ignition on.
With the DRBIIIt, read the active FCM DTCs.
NOTE: The SIACM RUN-START DRIVER OPEN code may not set until the
ignition key is turned off.
Turn the ignition off.
With the DRBIIIt, read the active SIACM FCM Diagnostic Trouble Codes.
Select the active SIACM FCM code displayed on the DRB.All
1. SIACM RUN-START DRIVER OPEN
Go To 2
2. SIACM RUN-START DRIVER OVER VOLTAGE
Go To 7
3. SIACM RUN-START SHORT TO GROUND
Go To 8
4. SIACM RUN-START DRIVER OVER CURRENT
Go To 8
5. SIACM RUN-START DRIVER OVER TEMP
Go To 8
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
2WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
WARNING: IF THE SIDE IMPACT AIRBAG CONTROL MODULE IS
DROPPED AT ANY TIME, IT MUST BE REPLACED.
Disconnect the Left Side Impact Airbag Control Module.
NOTE: When the ignition key is turned off, the FCM will supply a diagnostic
voltage to the SIACM Run-Start Driver circuit for approximately 60 sec-
onds.
Measure the voltage of the SIACM Run-Start Driver circuit between the Left Side
Impact Airbag Control Module connector and ground.
Turn the ignition switch ON and observe the diagnostic voltage on the SIACM
Run-Start circuit.
Select the results from the list below?All
Is the voltage between 1.0 and 2.2 volts
Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
Is the voltage between 2.4 and 5.0 volts
Go To 3
No Voltage present?
Go To 4
NOTE: When reconnecting airbag system components the Ignition must be
turned off and the Battery must be disconnected.
48
AIRBAG
FCM, SIACM RUN-START DRIVER OPEN - ACTIVE ÐContinued

POSSIBLE CAUSES
LEFT SIDE IMPACT AIRBAG CONTROL MODULE, ACTIVE OR STORED CODE
TEST ACTION APPLICABILITY
1WARNING: TURN THE IGNITION OFF, DISCONNECT THE BATTERY AND
WAIT TWO MINUTES BEFORE PROCEEDING.
WARNING: IF THE SIDE IMPACT AIRBAG CONTROL MODULE IS
DROPPED AT ANY TIME, IT MUST BE REPLACED.
If there are no possible causes remaining, view repair.All
Repair
Replace the Left Side Impact Airbag Control Module in accordance
with Service Instructions. WARNING: Make sure the battery is
disconnected and wait 2 minutes before proceeding. Erase DTCs
in all Modules.
Perform AIRBAG VERIFICATION TEST - VER 1.
NOTE: When reconnecting Airbag system components, the ignition must be
turned off and the battery must be disconnected.
54
AIRBAG
LEFT SIACM ACCELEROMETER 1 - ACTIVE ÐContinued

LEFT SIACM, SEAT SQUIB SHORT TO GROUND - STORED
When Monitored: When the ignition is on, the Left SIACM monitors the resistance of the
left Seat Squib circuits for low resistance.
Set Condition: The Left SIACM has detected a short to ground in the left Seat Squib
circuits.
ORC, INTERROGATE LEFT SIACM - STORED
When Monitored: With ignition on, the ORC monitors the PCI Bus for a Left SIACM
status message containing the airbag warning lamp9On or OFF9request. The status
message is sent to the ORC once each second or upon any change in the active DTCs.
Set Condition: The Code will set, if the ORC receives an9Lamp On9status message from
the Left SIACM. NOTE: This indicates that there was an active diagnostic trouble code in
the Left SIACM.
ORC, NO LEFT SIACM MESSAGE - STORED
When Monitored: With ignition on, the ORC monitors the PCI Bus for the Left SIACM
status message. The Left SIACM transmits the status message to the ORC at 1 - second
intervals.
Set Condition: If the ORC fails to see the Left SIACM status message on the PCI Bus for
10 seconds the code will set.
56
AIRBAG
LEFT SIACM, NO PCI TRANSMISSION - STORED ÐContinued