Isuzu Trooper (1998-2002 year). Manual - part 783
TRANSMISSION CONTROL SYSTEM (4L30–E)
7A1–41
Conditions For Clearing The DTC
D
The DTC can be cleared from the PCM history by
using a scan tool.
D
The DTC will be cleared from history when the vehicle
has achieved 40 warmup cycles without a failure
reported.
D
The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled “off”
long enough to power down the PCM.
Diagnostic Aids
D
Check harness routing for a potential short to ground
in circuit RED/WHT. Scan tool TFT display should rise
steadily to about 100
°
C (212
°
F), then stabilize.
D
Inspect the wiring for poor electrical connection at the
PCM and at the transmission 16–way connectors.
Look for possible bent, backed out, deformed or
damaged terminals. Check for weak terminal tension
as well. Also check for a chafed wire that could short
to bare metal or other wiring. Inspect for a broken wire
inside the insulation.
D
When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.
D
The temperature to resistance value scale may be
used to test the TFT sensor at the various
temperature levels to evaluate the possibility of a
“skewed” (mis–scaled) sensor.
A “skewed” sensor could result in delayed garage
shifts or TCC complaints.
D
Verify customer driving habits, trailer towing, etc.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This test checks for a short to ground or a “skewed”
sensor.
4. This test checks for an internal fault within the
transmission by creating an open.
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input
Step
Action
Yes
No
1
Were you sent here from the “Powertrain On–Board Diagnostic
(OBD) System Check”?
Go to Step 2
Go to OBD
System Check
Refer to
Driveability and
Emissions in
Engine section
2
Perform the transmission fluid checking procedure. Refer to
Checking Transmission Fluid Level and Condition in Automatic
Transmission (4L30–E) section.
Was the fluid checking procedure performed?
Go to Step 3
Refer to
Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30–E) section
3
1. Install the scan tool.
2. With the engine “off”, turn the ignition switch “on”.
NOTE: Before clearing DTC(s), use the scan tool to record “Freeze
Frame” and “Failure Records” for reference, as data will be lost
when the “Clear Info” function is used.
3. Record the DTC “Freeze Frame” and “Failure Records”.
Does the scan tool display a TFT sensor signal voltage less than
0.4 volts?
Go to Step 4
Go to Diagnostic
Aids
4
1. Turn the ignition “off”.
2. Disconnect the transmission 16–way connector H–69.
3. Turn the ignition “on”.
Does the TFT signal voltage change to match the voltage 4.92
volts?
Go to Step 5
Go to Step 10
5
Using the J39200 DVOM, measure the resistance between
terminals M7–4(F) and M7–1(E).
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 6