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 is9lock9position. 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 the wire and eventu-
ally cause the wire to fail because of corrosion.
Be careful when performing electrical tests so as
to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, a
second DTC could be set, making diagnosis of the
original problem more difficult.
When replacing a blown fuse, it is important to
use only a fuse having the correct amperage rating.
The use of a fuse with a rating other than indicated
may result in a dangerous electrical system over-
load. If a properly rated fuse continues to blow, it
indicates a problem in the circuit that must be
corrected.
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
DTC or symptom condition.
CAUTION: Before road testing a vehicle, be
sure that all components are reassembled.
During the test drive, do not try to read
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.
Road testing is an essential step in the diagnostic
process that must not be overlooked. Along with the
diagnostic information obtained from the DRBIIIt
Scan Tool and the original customer concern, the
road test helps verify the problem was current and
any repairs performed, fixed the vehicle correctly.
Always operate and observe the vehicle under ac-
tual driving conditions.
Just as important as the road test is, there are
preliminary inspections that should be performed
prior to the road test. Always check the fluid leveland condition before taking the vehicle on a road
test. Determine if the incorrect fluid is being used,
improper fluid will result in erratic transmission
operation.
Some of the conditions of incorrect fluid level are as
follows:
²Delayed engagement
²Poor shifting or erratic shifting
²Excessive noise
²Overheating
The next step is to verify that the shift linkage is
correctly adjusted. If the shift linkage is incorrectly
adjusted, a number of complaints can result.
The TCM monitors the Shift Lever Position (SLP)
continuously. If the linkage is incorrectly adjusted,
the TCM will sense a shift lever position that is not
correct for the gear chosen by the driver. This may
cause a DTC to be set.
The following complaints may also be the result of
an incorrectly adjusted or worn linkage:
²Delayed clutch engagement
²Erratic shifts
²Vehicle will drive in neutral
²Engine will not crank in park or neutral
²Gear shift linkage will be able to be shifted
without the key in the ignition
²Not able to remove the ignition key in park
²Parking pawl will not engage properly
The shift linkage should also be adjusted when
replacing the Transmission, repairing the valve
body, or when repairing any component between the
shift lever and the Transmission.
Some questions to ask yourself when performing
the road test are as follows:
²Is the complaint or concern what you think the
problem is, based on the drivers description of the
problem?
²Is the Transmission operating normally, or is
there a real problem?
²When does the problem occur?
²Is the problem only in one gear range?
²What temperature does the problem occur?
²Does the vehicle have to sit over night for the
problem to occur?
²Does the transmission go into Limp-in mode?
4.4.4 BULLETINS AND RECALLS
Always perform all Safety Recalls and Technical
Service Bulletins that are applicable to the prob-
lem.
7
GENERAL INFORMATION
5.0 REQUIRED TOOLS AND
EQUIPMENT
> DRBIIIt(diagnostic read-out box) - DRBIIIt
must use the latest release level.
> Jumper wires
> Test Light
> Ohmmeter
> Voltmeter
6.0 GLOSSARY OF TERMS
6.1 ACRONYMS
ABSAntilock Braking system
A/CAir conditioner
A/DAnalog to Digital conversion
APPAccelerator Pedal Position
CANController Area Network (Vehicle
Bus System)
CKTCircuit
DLCData Link Connector
DRBIIItDiagnostic Readout Box
DTCDiagnostic Trouble Code
ECMDiesel Engine Controller
EMCCElectronically Modulated Converter
Clutch
IODIgnition off-draw
ISSInput Speed Sensor (N2 and N3)
KK line communication bus
LEDLight Emitting Diode
MILMalfunction Indicator LampOSSOutput Speed Sensor (derived from
the ABS controller)
PEMCCPartial Electronically Modulated
Converter Clutch
PWMPulse width modulated
SKREEMSentry Key Remote Entry Module
SLAShift Lever Assembly
SWSwitch
TCCTorque Converter Clutch
TCMTransmission Control Module
TPThrottle Position
TRDTorque Reduction
TTSTransmission Temperature Sensor
1-2/4-5
solenoidcontrols the shift into and out of
2nd gear or 5th gear.
V2-3 so-
lenoidcontrols the shift into and out of 3rd
gear
V3-4 so-
lenoidcontrols the shift into and out of 4th
gear
VTCC
solenoidis pulse width modulated and con-
trols the TCC clutch
Shift
Pressure
Solenoidis a pulse width modulated solenoid
and controls the hydraulic pressure
to the shift elements.
Modula-
tion
pressure
solenoidis a pulse width modulated solenoid
and controls the hydraulic system
pressure
6.2 DEFINITIONS
Driving cycle counter) -The starts since first set
counter indicates the number of driving cycles since
the first occurrence of an error.
8
GENERAL INFORMATION
Symptom:
*NO RESPONSE FROM SHIFTER ASSEMBLY
POSSIBLE CAUSES
CHECK POWERS AND GROUNDS TO THE SHIFTER ASSEMBLY
CONTROLLER ANTILOCK BRAKE
K-ABS, SHIFTER ASSEMBLY CIRCUIT SHORTED TO GROUND
CONTROLLER ANTILOCK BRAKE
K-ABS, SHIFTER ASSEMBLY CIRCUIT SHORTED TO VOLTAGE
K-ABS, SHIFTER ASSEMBLY CIRCUIT OPEN
SHIFTER ASSEMBLY
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Shifter Assembly harness connector.
Check each power and ground circuit to the module.
Were any problems found?All
Ye s!Refer to the wiring diagrams located in the service information to
help isolate an open or shorted condition. Repair as necessary.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Go To 2
2 Turn the ignition off.
Disconnect the Shifter Assembly harness connector.
Disconnect the DRBIIItfrom the DLC.
Measure the resistance between ground and the K-ABS, Shifter Assembly circuit.
Is the resistance below 5.0 ohms?All
Ye s!Go To 3
No!Go To 4
3 Turn the ignition off.
Disconnect the CAB harness connector.
Measure the resistance between ground and the K-ABS, Shifter Assembly circuit.
Is the resistance below 5.0 ohms?All
Ye s!Repair the K-ABS, Shifter Assembly circuit for a short to ground.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Replace the Controller Antilock Brake in accordance with the
service information.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
10
COMMUNICATION
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the DRBIIItfrom the DLC.
Disconnect the Shifter Assembly harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the K-ABS, Shifter Assembly
circuit.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Go To 5
No!Go To 6
5 Turn the ignition off.
Disconnect the Controller Antilock Brake harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the K-ABS, Shifter Assembly
circuit.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Repair the K-ABS, Shifter Assembly circuit for a short to voltage.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Replace the Controller Antilock Brake in accordance with the
service information.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
6 Turn the ignition off.
Disconnect the Shifter Assembly harness connector.
Disconnect the DRBIIItfrom the DLC.
Measure the resistance of the K-ABS, Shifter Assembly circuit between the Shifter
Assembly connector and the DLC.
Is the resistance below 5.0 ohms?All
Ye s!Replace the Shifter Assembly in accordance with the Service
Information.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
No!Repair the K-ABS, Shifter Assembly circuit for an open.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1.
11
COMMUNICATION
*NO RESPONSE FROM SHIFTER ASSEMBLY ÐContinued
Symptom:
BACKUP LAMP CKT SHORT TO GROUND
POSSIBLE CAUSES
BACKUP LAMP CIRCUIT SHORT TO GROUND
SHIFT LEVER ASSEMBLY
TEST ACTION APPLICABILITY
1 Turn the ignition off to the lock position.
Disconnect the Shift Lever Assembly harness connector.
Isolate the Backup Lamp circuit, remove the Backup Lamp bulbs.
NOTE: Check Backup Lamp bulbs and socket for a short or corrosion.
Measure the resistance between ground and the Backup Lamp circuit.
Is the resistance below 5.0 ohms?All
Ye s!Repair the Backup Lamp circuit for a short to ground.
No!Replace the Shift Lever Assembly per the Service Information.
14
SHIFT LEVER ASSEMBLY
Symptom:
BACKUP LAMP CKT SHORT TO VOLTAGE OR OPEN
POSSIBLE CAUSES
BACKUP LAMP CIRCUIT OPEN
BACKUP LAMP CIRCUIT SHORT TO VOLTAGE
SHIFT LEVER ASSEMBLY
TEST ACTION APPLICABILITY
1 Start the engine.
While back probing, measure the voltage of the Backup Lamp circuit.
Is the voltage above 0.5 volts?All
Ye s!Go To 2
No!Go To 3
2 Turn the ignition off to the lock position.
Disconnect the Shift Lever Assembly harness connector.
Start the engine.
Measure the voltage of the Backup Lamp circuit in the Shift Lever Assembly harness
connector.
Is the voltage above 0.5 volts?All
Ye s!Repair the Backup Lamp circuit for a short to voltage.
No!Replace the Shift Lever Assembly per the Service Information.
3 Turn the ignition off to the lock position.
Disconnect the Shift Lever Assembly harness connector.
Remove the Backup Lamp bulb(s).
Connect a jumper wire between Shift Lever Assembly circuit and B(+).
Using a 12-volt test light connected to 12-volts, check the Backup Lamp circuit in the
Backup Lamp socket(s).
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Replace the Shift Lever Assembly per the Service Information.
No!Repair the Backup Lamp circuit for an open.
15
SHIFT LEVER ASSEMBLY
Symptom:
BACKUP LAMP SUPPLY CIRCUIT OPEN
POSSIBLE CAUSES
FUSED IGNITION SWITCH OUTPUT OPEN
SHIFT LEVER ASSEMBLY
TEST ACTION APPLICABILITY
1 Turn the ignition off to the lock position.
Disconnect the Shift Lever Assembly harness connector.
Start the engine.
Using a 12-volt test light connected to ground, check the Fused Ignition Switch
Output circuit.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Replace the Shift Lever Assembly per the Service Information.
No!Repair the Fused Ignition Switch Output circuit for an open. If
the fuse is open, make sure to check for a short to ground.
16
SHIFT LEVER ASSEMBLY
Symptom:
CAN BUS CIRCUIT
POSSIBLE CAUSES
CAN COMMUNICATION FAILURE
CAN BUS (+) OR (-) OPEN
SHIFT LEVER ASSEMBLY
TEST ACTION APPLICABILITY
1 With the DRBIIIt, read the stored and active DTCs for all modules on the CAN bus.
Are other modules reporting CAN bus DTCs?All
Ye s!Refer to the reporting category and perform the appropriate
symptom. If the ECM is reporting a CAN bus failure, refer to its
respective test first.
No!Go To 2
2 Turn the ignition off to the lock position.
Disconnect the ECM harness connector.
Disconnect the SLA harness connector.
Measure the resistance of both the CAN bus (+) and CAN bus (-) circuits from the
ECM harness connector to the SLA harness connector.
Is the resistance above 5.0 ohms and/or either circuit?All
Ye s!Repair the CAN bus (+) and/or (-) circuits for an open.
No!Replace the Shift Lever Assembly per the Service Information.
17
SHIFT LEVER ASSEMBLY