3.3.1
HARD CODE
Any Diagnostic Trouble Code (DTC) that is set
whenever the system or component is monitored is
a HARD code. This means that the problem is there
every time the Transmission Control System checks
that system or component. Some codes will set
immediately at start up and others will require a
road test under specific conditions. It must be
determined if a code is repeatable (Hard) or inter-
mittent before attempting diagnosis.
3.3.2
ONE TRIP FAILURES
A One Trip Failure, when read from the Trans-
mission Control System, is a hard OBDII (EURO
STAGE III OBD) code that has not matured for the
full 5 minutes to a hard fault. This applies to codes
that will only set after 5 minutes of substituted gear
operation.
3.3.3
INTERMITTENT CODE
A diagnostic trouble code that is not there every
time the Transmission Control System checks the
circuit or function is an a intermittent code. Some
intermittent codes are caused by wiring or connec-
tor problems. However intermittent gear ratio
codes are usually caused by intermittent hydraulic
seal leakage in the clutch and/or accumulator cir-
cuits. Problems that come and go like this are the
most difficult to diagnose, they must be looked for
under the specific conditions that cause them.
3.3.4
STARTS SINCE SET COUNTER
For the most recent code, the Starts Since Set
counter counts the number of times the vehicle has
started since it was last set. The counter will count
up to 255 starts. Note that this code only applies to
the last or most recent code set.
When there are no diagnostic trouble codes stored
in memory, the DRBIII
t will display NO DTC’S
PRESENT and the reset counter will show
‘‘STARTS SINCE CLEAR = XXX’’
The number of starts helps determine if the
diagnostic trouble code is hard or intermittent.
– If the count is less than 3, the code is usually a
hard code.
– If the count is greater than 3, it is considered
an intermittent code. This means that the
engine has been started most of the time
without the code recurring.
3.3.5
TROUBLE CODE ERASURE
A Diagnostic trouble code will be cleared from
control module memory if it has not reset for 40
warm-up cycles.
A warm-up cycle is defined as sufficient vehicle
operation such that the coolant temperature has
risen by at least 22°C (40° F) from engine starting
and reaches a minimum temperature of 71°C
(160° F).
The Malfunction Indicator Lamp (MIL) will turn
off after 3 good trips or when the DTC’s are cleared
from the control module.
3.3.6
QUICK LEARN
The Quick Learn function customizes adaptive
parameters of the control module to the transmis-
sion characteristics of a vehicle. This gives the
customer improved ‘‘as received’’ shift quality com-
pared to the initial parameters stored in the control
module.
Notes about Quick Learn Features
The nature of the Quick Learn function requires
that certain features must be taken into consider-
ation.
> Quick Learn should generally not be used as a
repair procedure unless directed by a repair or
diagnostic procedure. If the transmission sys-
tem is exhibiting a problem that you think is
caused by an invalid CVI, you should try to
relearn the value by performing the appropri-
ate driving maneuvers. In most cases, if Quick
Learn makes a vehicle shift better, the vehicle
will return with the same problem.
> Before performing Quick Learn, it is impera-
tive that the vehicle be shifted into OD with
the engine running and the oil level set to the
correct level. This step will purge air from the
clutch circuits to prevent erroneous clutch
volume values, which could cause poor initial
shift quality.
> If a new control module is installed on a
vehicle with a HOT engine, Quick Learn will
cause the control module to report a cold
calculated oil temperature. This requires
monitoring the calculated oil temperature us-
ing the DRBIII
t. If the temperature is below
15 C (60° F) , the transmission must be run at
idle or driven in gear until the temperature
goes above 15 C (60° F). If the temperature is
above 93C (200° F), the transmission must
cool to below 93 C (200° F).
> First gear is engaged in overdrive after Quick
Learn is completed. Place the vehicle in park
after performing Quick Learn.
The Quick Learn function should be performed:
– Upon installation of a new service control
module
– After replacement or rebuild of internal trans-
mission components or the torque converter
– If one or more of the clutch volumes indexes
(CVI’s) contain skewed readings because of
abnormal conditions.
3
GENERAL INFORMATION