ISUZU AXIOM 2002 Service Repair Manual

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

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±45
DTC P0722 Automatic Transmission Output Speed Sensor (OSS) Low Input
D07R200006
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 ªBº
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 3000 and 7000 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.

For lamp illuminate refer to
DTC type definition (type
B).
Conditions For Clearing The MIL/DTC

The PCM will turn off the MIL and 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 ªoffº
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 or massage the wiring harness
while observing test equipment for a change.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
4. This test checks the OSS circuit.
5. This test checks the integrity of the OSS.
7. This test checks the 5±volt and ground circuit of the
PCM.

7A1±46
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0722 Automatic Transmission Output Speed Sensor (OSS) 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
21. 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.
4. Raise the drive wheels.
5. Start the engine.
6. Place the transmission in any drive range.
With the drive wheels rotating, does the ªTrans Output Speedº
increase with the drive wheel speed?
Go to Diagnostic
Aids
Go to Step 3
3Check for the most current and/or incorrect calibration.
Is the calibration current?
Go to Step 16Go to Step 4
41. Turn the ignition ªoffº.
2. Disconnect the E35 (RED) PCM connector.
3. Using the J39200 DVOM, measure the resistance between
harness connector terminals E35±22 and E35±55.
Is the reading 3000 ohms?
Go to Step 5Go to Step 6
51. Select AC volts.
2. Rotate the rear wheels, ensuring the driveshaft is turning.
Is the voltage greater than 0.5 volts?
Go to Step 7Go to Step 8
6Inspect circuits BLU/YEL and BLU/GRN for a poor connection or
an open circuit.
Was a problem found?
Go to Step 17Go to Step 8
71. Reconnect the E35 (RED) PCM connector.
2. Disconnect the OSS harness from the OSS.
3. With the engine ªoffº, turn the ignition ªonº.
4. Using the J 39200 DVOM, measure the voltage at the OSS
harness connector terminals E44±1 and E44±2.
Is the reading between 4.0 to 5.1 volts?
Go to Step 16Go to Step 10
81. Remove the OSS.
2. Check the output shaft speed sensor rotor for damage or
misalignment. Refer to
Speed Sensor (Extension Assembly)
in Automatic Transmission (4L30±E) section.
Was a problem found?Go to Step 17Go to Step 9
9Replace the OSS.
Is the replacement complete?
Go to Step 17Ð
10Was the reading in step 7 less than 4.0 volts?Go to Step 12Go to Step 11
11Was the reading in Step 7 greater than 5.1 volts?Go to Step 15Ð
12Using the J 39200 DVOM to chassis ground, measure the voltage
on circuit BLU/YEL.
Is the reading between 4.0 to 5.1 volts?
Go to Step 13Go to Step 14

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±47
DTC P0722 Automatic Transmission Output Speed Sensor (OSS) Low Input (Cont'd)
StepNo Ye s Action
13Repair the open in circuit BLU/GRN.
Is the repair complete?
Go to Step 17Ð
14Check circuit BLU/YEL for a short to ground or open.
Was a problem found and corrected?
Go to Step 17Go to Step 16
15Repair the short to B+ in circuit BLU/YEL.
Is the repair complete?
Go to Step 17Ð
16Replace the PCM. Refer to Powertrain Control Module (PCM) in
automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 17Ð
171. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and operate the vehicle under the
following conditions:
Transmission output speed is greater than 101 rpm for 3
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

7A1±48
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0723 Automatic Transmission Output Speed Sensor (OSS) Intermittent
D07R200006
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 fast decrease of output speed when
engine running in a drive gear range. This is a type ªBº
DTC.
Conditions For Setting The DTC
Drive range

Engine running time is greater than 5 seconds.

Output speed is greater than 1300 rpm for 2 second.

NORAW±NOLAST < 200 rpm for 2 seconds.

NORAW: Latest raw data of output shaft speed.

NOLAST: Fitered previous data of output speed.

Transmission negative output speed change is
greater than 1300 rpm.

Conditions met for 3 seconds.
Action During Detection Time

Output speed value is frozen
Action Taken When The DTC Sets

Fixed to 4th gear.

Maximum line pressure.

Inhibit TCC engagement.

For lamp illuminate refer to
DTC type definition (type
B).
Conditions For Clearing The MIL/DTC

The PCM will turn off the MIL and 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 ªoffº
long enough to power down the PCM.
Diagnostic Aids

A OSS DTC P0723 will set when output speed has
been detected and is lost.

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:
4. This test checks the OSS circuit.
5. This test checks the integrity of the OSS.
7. This test checks the 5±volt and ground circuit of the
PCM.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±49
DTC P0723 Automatic Transmission Output Speed Sensor (OSS) Intermittent
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
21. 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.
4. Raise the drive wheels.
5. Start the engine.
6. Place the transmission in any drive range.
With the drive wheels rotating, does the ªTrans Output Speedº
increase with the drive wheel speed?
Go to Diagnostic
Aids
Go to Step 3
3Check for the most current and/or incorrect calibration.
Is the calibration current?
Go to Step 16Go to Step 4
41. Turn the ignition ªoffº.
2. Disconnect the E35 (RED) PCM connector.
3. Using the J39200 DVOM, measure the resistance between
harness connector terminals E35±22 and E35±55.
Is the reading 3,000 ohms?
Go to Step 5Go to Step 6
51. Select AC volts.
2. Rotate the rear wheels, ensuring the driveshaft is turning.
Is the voltage greater than 0.5 volts?
Go to Step 7Go to Step 8
6Inspect circuits BLU/YEL and BLU/GRN for a poor connection or
an open circuit.
Was a problem found?
Go to Step 17Go to Step 8
71. Reconnect the E35 (RED) PCM connector.
2. Disconnect the OSS harness from the OSS.
3. With the engine ªoffº, turn the ignition ªonº.
4. Using the J 39200 DVOM, measure the voltage at the OSS
harness connector terminals E44±1 and E44±2.
Is the reading between 4.0 to 5.1 volts?
Go to Step 16Go to Step 10
81. Remove the OSS.
2. Check the output shaft speed sensor rotor for damage or
misalignment. Refer to
Speed Sensor (Extension Assembly)
in Automatic Transmission (4L30±E) section.
Was a problem found?Go to Step 17Go to Step 9
9Replace the OSS.
Is the replacement complete?
Go to Step 17Ð
10Was the reading in step 7 less than 4.0 volts?Go to Step 12Go to Step 11
11Was the reading in Step 7 greater than 5.1 volts?Go to Step 15Ð
12Using the J 39200 DVOM to chassis ground, measure the voltage
on circuit BLU/YEL.
Is the reading between 4.0 to 5.1 volts?
Go to Step 13Go to Step 14

7A1±50
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0723 Automatic Transmission Output Speed Sensor (OSS) Intermittent (Cont'd)
StepNo Ye s Action
13Repair the open in circuit BLU/GRN.
Is the repair complete?
Go to Step 17Ð
14Check circuit BLU/YEL for a short to ground or open.
Was a problem found and corrected?
Go to Step 17Go to Step 16
15Repair the short to B+ in circuit BLU/YEL.
Is the repair complete?
Go to Step 17Ð
16Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 17Ð
171. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and operate the vehicle under the
following conditions:
Transmission output speed is greater than 101 rpm for 3
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±51
DTC P0724 Brake Switch Circuit High (Stuck Off)
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 a closed brake switch circuit (12
volts, high input) during decelerations, then DTC P0724
sets. DTC P0724 is a type D DTC.
Conditions For Setting The DTC

No OSS Assy. DTCs P0722 or P0723.

The PCM detects a closed brake switch circuit (12
volts) without changing and the following events
occur seven consecutive times.

The vehicle speed is greater than 32 km/h (20 mph)
for 4 seconds.

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

then the vehicle speed is less than 8 km/h (5 mph).
Action Taken When The DTC Sets

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

DTC P0724 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 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.

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

Check brake switch for proper mounting and
adjustment.

7A1±52
TRANSMISSION CONTROL SYSTEM (4L30±E)
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
2. This step isolates the brake switch as a source for
setting the DTC.
DTC P0724 Brake Switch Circuit High (Stuck Off)
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 DTC Failure Records, then clear the DTC(s).
4. Select ªBrake Switchº on the scan tool.
5. Disconnect the brake switch connector from the brake switch.
Did the TCC brake switch status change from ªClosedº to ªOpenº?
Go to Step 3Go to Step 4
3Replace the brake switch.
Is the replacement complete?
Go to Step 6Ð
4Inspect circuit BRN/RED for a short to B+ condition. Repair the
circuit if necessary.
Did you find a short to B+ condition?
Go to Step 6Go to Step 5
5Replace the PCM.
Is the replacement complete?
Go to Step 6Ð
6In order to verify your repair, perform the following procedure:
1. Select DTC.
2. Select ªClear Infoº.
3. With the engine ªoffº turn the ignition switch to the ªonº position.
4. Apply the brake pedal.
5. Verify that the brake switch status indicates ªOpenº (0 volts) for
2 seconds.
6. Select Specific DTC. Enter DTC P0724.
Has the test run and passed?
System OK
Begin the
diagnosis again.
Go to
Step 1

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±53
DTC P0730 Gear Error Without Input Speed
D07RY00055
Circuit Description

The Powertrain Control Module (PCM) calculates the
slippage of the converter and transmission based
upon the engine speed, the output speed, and the
current gear ratio.

The slippage of the converter at a high enough engine
speed is low. The transmission should not slip more
than a given value when there is no shift.

This DTC detects a slip at each gear. This is a type
ªCº DTC.
Conditions For Setting The DTC

No Output Speed Sensor DTC(s) P0722, P0723.

Not in Park, Neutral, or Reverse.

Engine speed is greater than 3,500 rpm.

3 seconds since upshift.
No Transmission Range Switch DTC(s) P0705,
P0706.

3 seconds since downshift.

3 seconds since garage shift (N"D).

And one of the following conditions occur:
± Slip is greater than 508 rpm in 1st gear.
± Slip is greater than 468 rpm in 2nd gear.
± Slip is greater than 449 rpm on 3rd gear.
± Slip is greater than 440 rpm on 4th gear.

All conditions met for 5.5 seconds.Action Taken When The DTC Sets

Maximum line pressure.

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