OPEL FRONTERA 1998 Workshop Manual

7A1–36
TRANSMISSION CONTROL SYSTEM (4L30–E)
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input
D07RW029
Circuit Description
The TFT sensor is a thermister that controls the signal
voltage to the PCM. The PCM supplies a 5–volt reference
signal to the sensor on circuit RED/BLK–GRN/RED.
When the transmission fluid is cold, the sensor resistance
is high. The PCM detects high signal voltage. As the
transmission fluid temperature increases to the normal
operating temperature of 100
C (212F), the sensor
resistance becomes less and the voltage decreases to
1.5 to 2 volts. With transmission fluid over temperature
and DTC P0218 also set, check the transmission cooling
system.
This DTC detects a continuous short to ground in the TFT
signal circuit or the TFT sensor. This is a type “D” DTC.
Conditions For Setting The DTC
Battery voltage is between 10 and 16 volts.
Ignition is “on”.
TFT sensor indicating a voltage less than 0.4 volts.
All conditions met for 20 seconds.
Action Taken When The DTC Sets
Transmission default temperature will be:
80
C (176F) if engine temperature code is set.
100
C (212F) if engine temperature is warm.
80
C (176F) if engine run time is greater than 5
minutes.
21
C (69.8F) if engine run time is less than 5
minutes.
The PCM will not illuminate the CHECK TRANS
Lamp.
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 “off”
long enough to power down the PCM.
Diagnostic Aids
Check harness routing for a potential short to ground
in circuit RED/BLK–GRN/RED. Scan tool TFT
display should rise steadily to about 100
C (212F),
then stabilize.
Inspect the wiring for poor electrical connection at the
PCM and at the transmission 16–way connector.
Look for possible bent, backed out, deformed or
damaged terminals. Check for weak terminal tension
as we ll. A lso ch eck fo r a ch af e d w ire th at cou l d s ho r t
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.
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.
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.

TRANSMISSION CONTROL SYSTEM (4L30–E)7A1–37
Resistance Chart
CFResistance (k)
–40–40672
03265
206825
801762.5
1202480.78
1503040.37
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input
StepActionYe sNo
1Perform 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 2
Refer to
Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30–E) section
21. 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 3
Go to Diagnostic
Aids
31. Turn the ignition “off”.
2. Disconnect the transmission 16–way connector H–53.
3. Turn the ignition “on”.
Does the TFT signal voltage change to match the voltage 4.92
volts?
Go to Step 4Go to Step 9
4Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5 (D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 5
51. Disconnect the transmission 5–way connector M–6.
2. Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5(D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 6
61. Remove the transmission oil pan. Refer to Transmission Oil
Temperature Sensor (Adapter 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 8Go to Step 7
71. Disconnect the internal wiring harness at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 8
8Replace the TFT Sensor.
Is the replacement complete?
Go to Step 12—

7A1–38
TRANSMISSION CONTROL SYSTEM (4L30–E)
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Input (Cont’d)
StepNo Ye s Action
9Check circuit RED/BLK–GRN/RED for a short to ground.
Was a problem found?
Go to Step 12Go to Step 10
10Check the PCM for faulty connections.
Was a problem found?
Go to Step 12Go to Step 11
11Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30–E) section.
Is the replacement complete?
Go to Step 12—
121. After the repair is complete, use the scan tool to select “DTC”,
then “Clear Info” 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 “DTC info”.
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
D07RW029
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–GRN/RED.
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 (212F), 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 “D”
DTC.
Conditions For Setting The DTC
Battery voltage is between 10 and 16 volts.
Ignition is “on”.
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 (176F) if engine temperature code is set.
100
C (212F) if engine temperature is warm.
80
C (176F) if engine run time is greater than 5
minutes.
21
C (69.8F) if engine run time is less than 5
minutes.
The PCM will not illuminate the CHECK TRANS
Lamp.
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 “off”
long enough to power down the PCM.
Diagnostic Aids
Inspect the wiring for poor electrical connection at the
PCM and at the transmission 16–way connector.
Look for possible bent, backed out, deformed or
damaged terminals. Check for weak terminal tension
as we ll. A lso ch eck fo r a ch af e d w ire th at cou l d s ho r t
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
“skewed” (mis–scaled) sensor.
A “skewed” 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.

7A1–40
TRANSMISSION CONTROL SYSTEM (4L30–E)
5. This test checks the TFT sensor and internal wiring
harness.
Resistance Chart
CFResistance (k)
–40–40672
03265
206825
801762.5
1202480.78
1503040.37
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input
StepActionYe sNo
1Perform 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 2
Refer to
Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30–E) section
21. 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 “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 greater
than 4.86 volts?
Go to Step 3
Go to Diagnostic
Aids
31. Turn the ignition “off”.
2. Disconnect the transmission 16–way connector H–53.
3. Install a fused jumper wire from terminal 3(C) to 5(D) on the
engine harness.
4. Turn the ignition “on”.
Does the TFT signal voltage drop to less than 0.4 volts?
Go to Step 4Go to Step 9
41. Turn the ignition “off”.
2. Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5(D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 5
51. Disconnect the transmission 5–way connector M–6.
2. Using the J39200 DVOM, measure the resistance between
terminals 3(C) and 5(D).
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 6
61. Remove the transmission oil pan.
2. Check the internal wiring harness for an open. Refer to
Transmission Oil Temperature Sensor (Adapter Case) in
Automatic Transmission (4L30–E) section.
Was a problem found and corrected?
Go to Step 13Go to Step 7
71. Disconnect the internal wiring harness at the TFT sensor.
2. Measure the resistance of the TFT sensor.
Is the resistance within specifications? (See Resistance Chart.)
Go to Diagnostic
Aids
Go to Step 8

TRANSMISSION CONTROL SYSTEM (4L30–E)7A1–41
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit High Input (Cont’d)
StepNo Ye s Action
8Replace TFT sensor. Refer to Transmission Oil Temperature
Sensor (Adapter Case) in Automatic Transmission (4L30–E)
section.
Is the replacement complete?
Go to Step 13—
9Check circuit RED/BLK–GRN/RED for an open or short to B+.
Was a problem found?
Go to Step 13Go to Step 10
10Check circuit GRY–GRN for an open.
Was a problem found?
Go to Step 13Go to Step 11
11Check the PCM for faulty or intermittent 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 13—
131. After the repair is complete, use the scan tool to select “DTC”,
then “Clear Info” 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 “DTC Info”.
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 TCC Brake Switch Circuit High (Stuck On)
D07RW032
Circuit Description
The TCC brake switch is used to indicate brake pedal
status. The normally opened brake switch signal voltage
circuit is opened.
Brake switch supplies a B+ signal on circuit GRN/YEL to
the PCM when the brakes are applied. The PCM uses
this signal to deenergize the TCC solenoid when the
brakes are applied.
This DTC detects a closed brake switch during
accelerations. This is a type “D” DTC.
Conditions For Setting The DTC
No OSS DTCs P0722 or P0723.
The PCM detects a closed brake switch/circuit (12
volts) for 2 seconds, and the following events occur
seven consecutive times: vehicle speed is less than 8
km/h (5 mph); then vehicle speed is between 8 and 32
km/h (5 and 20 mph) for 4 seconds; then vehicle
speed is greater than 32 km/h (20 mph) for 4 seconds.
Action Taken When The DTC Sets
If throttle opening is greater than 10% and vehicle
speed is greater than 45 km/h (28 mph), then
disregard brake switch contingency for TCC off
mode.
The PCM will not illuminate the CHECK TRANS
Lamp.
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 “off”
long enough to power down the PCM.
Diagnostic Aids
Inspect the wiring for poor electrical connections at
the PCM and TCC 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.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This test checks for voltage at the brake switch.
6. This test checks the brake switch.
9. This test checks circuit GRN/YEL at the PCM.

TRANSMISSION CONTROL SYSTEM (4L30–E)7A1–43
DTC P0719 TCC Brake Switch Circuit High (Stuck On)
StepActionYe sNo
11. Install the scan tool.
2. With the engine “off”, turn the ignition switch “on”. If ABS code
is set, check applicable fuse.
NOTE: Before clearing DTC(s), use the scan tool to record “Failure
Records” for reference, as data will be lost when the “Clear Info”
function is used.
3. Record the DTC “Failure Records”.
4. Apply then release the brake pedal.
Does the scan tool display “TCC Brake Switch” as “closed” with
the brake pedal applied, and then display “open” when the brake
pedal is released?
Go to Diagnostic
Aids
Go to Step 2
21. Connect the test light to ground.
2. Back probe ignition feed circuit terminal B13–1 at the brake
switch.
Is the test light “on”?
Go to Step 3Go to Step 4
31. Connect the test light to ground.
2. Back probe circuit terminal B13–4 at the brake switch.
Is the test light “off”?
Go to Step 7Go to Step 5
4Repair the open in battery feed circuit terminal B13–1 to the brake
switch.
If fuse is open, check circuit terminal B13–4 for a short to ground.
Is the repair complete?
Go to Step 13—
5Disconnect brake switch connector B–13 and ignition switch “on”.
Is the test light “on”?
Go to Step 8Go to Step 6
6Check the brake switch short (B13–1 and B13–4).
Was a problem found?
Go to Step 9Go to Step 10
7Check circuit terminal B13–4 for a short to voltage.
Ignition switch “on”.
Is the test light “on”?
Go to Step 8Go to Step 10
81. Disconnect the J3 (BLUE) PCM connector.
2. Check circuit terminal B13–4 for a short to voltage.
Was a problem found?
Go to Step 13Go to Step 10
9Replace the brake switch.
Is the replacement complete?
Go to Step 13—
101. Turn the ignition “off”.
2. Reconnect the J3 (BLUE) PCM connector.
3. Turn the ignition “on”.
Does the scan tool display “TCC Brake Switch” as “open” with the
brake applied, then display “closed” with the brake pedal
released?
Go to Diagnostic
Aids
Go to Step 11
11Check the PCM for faulty or intermittent connections.
Was a problem found and corrected?
Go to Step 13Go to Step 12

7A1–44
TRANSMISSION CONTROL SYSTEM (4L30–E)
DTC P0719 TCC Brake Switch Circuit High (Stuck On) (Cont’d)
StepNo Ye s Action
12Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30–E) section.
Is the replacement complete?
Go to Step 13—
131. After the repair is complete, use the scan tool to select “DTC”,
then “Clear Info” function and ensure the following conditions
are met:
The PCM brake switch signal must indicate 0 volts for 1
seconds with the brake pedal applied.
2. Review the scan tool “DTC Info”.
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)7A1–45
DTC P0722 Transmission Output Speed Sensor (OSS) Low Input
D07RW006
Circuit Description
Output speed information is provided to the PCM by the
OSS, which is a permanent magnet (PM) generator. The
PM generator produces a pulsing AC voltage. The AC
voltage level and number of pulses increases as the
speed of the vehicle increases. The PCM then converts
the pulsing voltage to output speed, which is used for
calculations. The vehicle speed can be displayed with a
scan tool.
This DTC detects a low output speed when there is a high
engine speed in a drive gear range. This is a type “C”
DTC.
Conditions For Setting The DTC
No MAP DTCs P0107 or P0108, P0106, P1106,
P1107.
No TPS DTCs P0122 or P0123.
Not in Park or Neutral.
TP angle is greater than 10%.
Engine vacuum is between 0 and 70kPa.
Engine speed is between 3,000 and 7,000 rpm.
Transmission output speed is less than 0 rpm.
All conditions met for 5 seconds.
Action Taken When The DTC Sets
Fixed to 4th gear.
Maximum line pressure.
Inhibit TCC engagement.
The PCM will illuminate the CHECK TRANS Lamp.
Conditions For Clearing The MIL/DTC
The PCM will turn off the CHECK TRANS Lamp after
three consecutive ignition cycles without a failure
reported.
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 “off”
long enough to power down the PCM.
Diagnostic Aids
An OSS DTC P0722 will set when no output speed is
at detected at start off.
Inspect the wiring for poor electrical connection at the
PCM. 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.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
5. This test checks the OSS circuit.
6. This test checks the integrity of the OSS.
8. This test checks the 5–volt and ground circuit of the
PCM.