2002 ISUZU AXIOM transmission

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±37
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input
StepActionYe sNo
1Were you sent here from the ªPowertrain On±Board Diagnostic
(OBD) System Checkº?
Go to Step 2
Go to OBD
System Check
Refer to
Driveability and
Emissions in
Engine section
2Perform 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
31. Install the scan tool.
2. With the engine ªoffº, turn the ignition switch ªonº.
NOTE: Before clearing DTC(s), use the scan tool to record ªFreeze
Frameº and ªFailure Recordsº for reference, as data will be lost
when the ªClear Infoº function is used.
3. Record the DTC ªFreeze Frameº and ªFailure Recordsº.
Does the scan tool display a TFT sensor signal voltage less than
0.4 volts?
Go to Step 4
Go to Diagnostic
Aids
41. Turn the ignition ªoffº.
2. Disconnect the transmission 7±way connector E±42.
3. Turn the ignition ªonº.
Does the TFT signal voltage change to match the voltage 4.92
volts?
Go to Step 5Go to Step 10
5Using the J39200 DVOM, measure the resistance between
terminals E42±4(F) and E42±1(E).
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 6
61. Disconnect the transmission 7±way connector E±42.
2. Using the J39200 DVOM, measure the resistance between
terminals E42±4(F) and E42±1(E).
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 7
71. Remove the transmission oil pan. Refer to Transmission Oil
Temperature Sensor (Main Case) in Automatic Transmission
(4L30±E) section.
2. Check the internal wiring harness for a short to ground.
Was a problem found?
Go to Step 9Go to Step 8
81. Disconnect the internal wiring harness at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 9
9Replace the TFT Sensor.
Is the replacement complete?
Go to Step 13Ð
10Check circuit RED/BLK for a short to ground.
Was a problem found?
Go to Step 13Go to Step 11

7A1±38
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input (Cont'd)
StepNo Ye s Action
11Check the PCM for faulty connections.
Was a problem found?
Go to Step 13Go to Step 12
12Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 13Ð
131. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
TFT sensor indicates a voltage greater than 0.33 volts for 2
seconds.
2. Review the scan tool ªDTC infoº.
Has the last test failed or is the current DTC displayed?
Begin diagnosis
again
Go to
Step 1
Repair verified
Exit DTC table

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±39
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input
D07R200004
Circuit Description
The TFT sensor is a thermistor that controls the signal
voltage to the PCM. The PCM supplies a 5±volt reference
signal to the sensor on circuit RED/BLK. When the
transmission fluid is cold, the sensor resistance is high
and the PCM will sense high signal voltage. As the
transmission fluid temperature warms to the normal
operating temperature of 100
C (212
F), the sensor
resistance becomes less and the voltage decreases to
about 1.5 to 2 volts.
This DTC detects a continuous open or short to power in
the TFT signal circuit or the TFT sensor. This is a type ªDº
DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

Ignition is ªonº.

TFT sensor indicating a voltage greater than 4.86
volts.

All conditions met for 20 seconds.
Action Taken When The DTC Sets

Transmission default temperature will be:
80
C (176
F) if engine temperature code is set.
100
C (212
F) if engine temperature is warm.
80
C (176
F) if engine run time is greater than 5
minutes.
21
C (69.8
F) if engine run time is less than 5
minutes.

The PCM will not illuminate the Malfunction Indicator
Lamp (MIL).
Conditions For Clearing The DTC

The DTC can be cleared from the PCM history by
using a scan tool.
The DTC will be cleared from history when the vehicle
has achieved 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled ªoffº
long enough to power down the PCM.
Diagnostic Aids

Inspect the wiring for poor electrical connection at the
PCM and transmission 7-way connector. 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.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.

Scan tool displays transmission fluid temperature in
degrees. After transmission is operating, the
temperature should rise steadily to about 100
C
(212
F), then stabilize.

The temperature to resistance value scale may be
used to check the TFT sensor at the various
temperature levels to evaluate the possibility of a
ªskewedº (mis±scaled) sensor.
A ªskewedº sensor could result in hard shifts or TCC
complaints.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This check verifies problem in the TFT sensor circuit.
4. This test simulates a TFT sensor DTC P0712. If the
PCM recognizes the low signal voltage (high
temperature), and the scan tool displays 146
C
(295
F) or greater, the PCM and wiring are OK.
5. This test checks the TFT sensor and internal wiring
harness.

7A1±40
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input
StepActionYe sNo
1Were you sent here from the ªPowertrain On±Board Diagnostic
(OBD) System Checkº?
Go to Step 2
Go to OBD
System Check
Refer to
Driveability and
Emission in
Engine section
2Perform 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
31. Install the scan tool.
2. With the engine ªoffº, turn the ignition switch ªonº.
NOTE: Before clearing DTC(s), use the scan tool to record ªFreeze
Frameº and ªFailure Recordsº for reference, as data will be lost
when the ªClear Infoº function is used.
3. Record the DTC ªFreeze Frameº and ªFailure Recordsº.
Does the scan tool display a TFT sensor signal voltage greater
than 4.86 volts?
Go to Step 4
Go to Diagnostic
Aids
41. Turn the ignition ªoffº.
2. Disconnect the transmission 7±way connector E±42.
3. Install a fused jumper wire from terminal E42±4(F) to
E42±1(E) on the engine harness.
4. Turn the ignition ªonº.
Does the TFT signal voltage drop to less than 0.4 volts?
Go to Step 5Go to Step 10
51. Turn the ignition ªoffº.
2. Using the J39200 DVOM, measure the resistance between
terminals E42±4(F) and E42±1(E).
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 6
61. Disconnect the transmission 7±way connector E±42.
2. Using the J39200 DVOM, measure the resistance between
terminals E42±4(F) and E42±1(E).
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 7
71. Remove the transmission oil pan.
2. Check the internal wiring harness for an open. Refer to
Transmission Oil Temperature Sensor (Main Case) in
Automatic Transmission (4L30±E) section.
Was a problem found and corrected?Go to Step 14Go to Step 8
81. Disconnect the internal wiring harness at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications? (See Transmission Fluid
Temperature (TFT) Sensor Specifications.)
Go to Diagnostic
Aids
Go to Step 9
9Replace TFT sensor. Refer to Transmission Oil Temperature
Sensor (Main Case) in Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 14Ð

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±41
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input (Cont'd)
StepNo Ye s Action
10Check circuit RED/BLK for an open or short to B+.
Was a problem found?
Go to Step 14Go to Step 11
11Check circuit RED/WHT for an open.
Was a problem found?
Go to Step 14Go to Step 12
12Check the PCM for faulty or intermittent connections.
Was a problem found?
Go to Step 14Go to Step 13
13Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 14Ð
141. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
2. TFT sensor indicates a voltage less than 4.92 volts for 2
seconds.
3. Review the scan tool ªDTC Infoº.
Has the last test failed or is the current DTC displayed?
Begin diagnosis
again
Go to
Step 1
Repair verified
Exit DTC table

7A1±42
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0719 Brake Switch Circuit Low (Stuck On)
D07R200007
Circuit Description:
The brake switch indicates brake pedal status to the
Powertrain Control Module (PCM). The brake switch is a
normally±closed switch that supplies battery voltage on
circuit BRN/RED to the PCM. Applying the brake pedal
opens the switch, interrupting voltage to the PCM. When
the brake pedal is released, the PCM receives a constant
voltage signal. If the PCM receives a zero voltage signal
at the brake switch input, and the Torque Converter
Clutch (TCC) is engaged, the PCM de±energizes the
Torque Converter Clutch Solenoid Valve (TCC Sol.
Valve). The PCM disregards the brake switch input for
TCC scheduling if there is a brake switch circuit fault
(Refer to
Diagnostic Aids).
When the PCM detects an open brake switch circuit (0
volts, low input) during accelerations, then DTC P0719
sets. DTC P0719 is a type D DTC.
Conditions For Setting The DTC

No OSS Assy. DTCs P0722 or P0723.

The PCM detects an open brake switch or circuit (0
volts) for 15 minutes without changing for 2 seconds,
and the following events occur seven consecutive
times.

The vehicle speed is less than 8 km/h (5 mph).

then the vehicle speed is 8±32 km/h (5±20 mph) for
4 seconds.

then the vehicle speed is greater than 32 km/h (20
mph) for 4 seconds.
Action Taken When The DTC Sets

The PCM does not illuminate the Malfunction
Indicator Lamp (MIL).

DTC P0719 stores in PCM history.
Conditions For Clearing The DTC

A scan tool can clear the DTC from the PCM history.
The PCM clears the DTC from the PCM history if the
vehicle completes 40 warm±up cycles without a
failure reported.

The PCM cancels the DTC default actions when the
fault no longer exists and the ignition is OFF long
enough in order to power down the PCM.
Diagnostic Aids

Inspect the wiring for poor electrical connections at
the PCM and brake switch. 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.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.

Check customer driving habits and/or unusual driving
conditions (i.e. stop and go, highway).

Check brake switch for proper mounting and
adjustment.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±43
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This step isolates the brake switch as a source for
setting the DTC.

7A1±44
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0719 Brake Switch Circuit Low (Stuck On)
StepActionYe sNo
1Was the Powertrain On±Board Diagnostic (OBD) System Check
performed?
Go to Step 2
Go to Powertrain
OBD System
Check
21. Install the scan tool.
2. With the engine ªoff,º turn the ignition switch to the ªonº
position.
NOTE: Before clearing the DTC(s), use the scan tool in order to
record the ªFailure Recordsº for reference. Using the ªClear Infoº
function will erase the stored ªFailure Recordsº from the PCM.
3. Record the ªDTC Failure Recordsº, then clear the DTC(s).
4. Select ªTCC Brake Switchº on the scan tool.
5. Disconnect the brake switch connector from the brake switch.
6. Connect a test lamp from cavity I31±3 of the brake switch
connector to a known good ground.
Is the test lamp ON?
Go to Step 3Go to Step 4
3Install a J 36169±A Fused Jumper Wire from terminal I31±2 to
terminal I31±3 of the brake switch connector.
Did the TCC Brake Switch status change from Open to Closed?
Go to Step 7Go to Step 9
41. Remove the fuse ªTURN, BACK UPº.
2. Inspect the fuse for an open.
Is the fuse open?
Go to Step 5Go to Step 8
5Inspect circuit WHT/GRN for a short to ground condition. Repair
the circuit if necessary.
Did you find a short to ground condition?
Go to Step 11Go to Step 6
6Inspect circuit BRN/RED for a short to ground condition. Repair
the circuit if necessary.
Did you find a short to ground condition?
Go to Step 11Go to Step 10
7Replace the brake switch.
Is the replacement complete?
Go to Step 11Ð
8Inspect circuit WHT/GRN for an open condition. Repair the circuit
if necessary.
Did you find and correct an open condition?
Go to Step 11Ð
9Inspect circuit BRN/RED for an open.
Did you find an open condition?
Go to Step 11Go to Step 10
10Replace the PCM.
Is the replacement complete?
Go to Step 11Ð
11In order to verify your repair, perform the following procedure:
1. Select DTC.
2. Select Clear Info.
3. With the engine ªoff,º turn the ignition switch to the ªonº
position.
4. Do not depress the brake pedal.
5. Verify that the Brake Switch status indicates ªClosedº (12
volts) for 2 seconds.
6. Select Specific DTC. Enter DTC P0719.
Has the test run and passed?
System OK
Begin the
diagnosis again.
Go to
Step 1