2002 ISUZU AXIOM transmission

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).

7A1±54
TRANSMISSION CONTROL SYSTEM (4L30±E)

The PCM will illuminate the CHECK TRANS Lamp.

Turn force motor OFF.
Conditions For Clearing The DTC/CHECK
TRANS Lamp

The PCM will turn ªoffº the CHECK TRANS Lamp
after three consecutive ignition cycles without a
failure reported.

The DTC can be cleared from PCM memory by using
a scan tool.

The DTC can also be cleared from memory when the
vehicle has made 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC Actions Taken items
when the fault conditions no longer exist and the
ignition is cycles ªoffº long enough to power down the
PCM.
Diagnostic Aids

Check for intermittent output speed sensor circuit
problems.

Check for possible incorrect calibration. (PCM part
No., tire specification, and rear axle ratio)
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This step checks for possible low fluid level causing
slipping resulting in an undefined gear ratio.
4. This step checks for correct gear ratios for
commanded gears.
5. This step checks for low line pressure.
DTC P0730 Gear Error Without Input Speed
StepActionYe sNo
1Were you sent here from the ªOn±Board Diagnostic (OBD)
System Checkº?
Go to Step 2
Go to OBD
System Check
Refer to
Driveability and
Emission in
Engine section
2Visually inspect the transmission cooling system for fluid leaks.

Refer to
Chart 16: Possible Causes of Transmission Fluid
Leaks of Mechanical/Hydraulic Diagnosis Symptoms Index in
Automatic Transmission (4L30±E) section
Was condition found and corrected?Go to Step 7Go to Step 3
3Refer to Checking Transmission Fluid Level and Condition in
Automatic Transmission (4L30±E) section.
Has transmission fluid checking procedure been performed?
Go to Step 4
Go to Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30±E) section
41. Install the scan tool.
2. Turn the ignition switch to the ªonº position.
3. Engine not running.
NOTE: Before clearing DTC(s) use the scan tool to record the
ªFailure Recordsº for reference, as data will be lost when the ªClear
Infoº function is used.
4. Record the Failure Record data.
5. Use the scan tool snapshot mode to record transmission gear
ratios.
6. Drive vehicle in transmission gear ranges L, 2, 3, and D with
the engine speed is greater than 3,500 rpm for 5.5 seconds.
7. Record each transmission gear.
1st:2.73 ± 2.99
2nd:1.54 ± 1.71
3rd:0.93 ± 1.05
4th:0.66 ± 0.78
Does commanded gear ratio match ranges as shown?
Refer to
Diagnostic AidsGo to Step 5

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±55
DTC P0730 Gear Error Without Input Speed (Cont'd)
StepNo Ye s Action
5Perform line pressure check.

Refer to
Line Pressure Test in Automatic Transmission
(4L30±E) section.
Was condition found and corrected?Go to Step 7Go to Step 6
6Check for possible clutch slippage.

Refer to
Chart 6: Diagnostic Trouble Code (DTC) P0730 of
Mechanical/Hydraulic Diagnosis Symptoms Index in
Automatic Transmission (4L30±E) section.
Was condition found and corrected?Go to Step 7Ð
71. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear infoº function.
2. Operate the vehicle under the following conditions:

Drive the vehicle in D4 with the engine speed greater than
3,500 rpm to obtain anyone of the following gear ratios for
seven seconds.
1st 1:2.73 ± 1:2.99
2nd 1:1.54 ± 1:1.71
3rd 1:0.93 ± 1:1.05
4th 1:0.66 ± 1:0.78
Has the last test failed?
Begin diagnosis
again
Go to
Step 1
Repair verified
Exit DTC table

7A1±56
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0742 Torque Converter Clutch (TCC) System Stuck On
D07R200008
Circuit Description
The PCM energizes the TCC solenoid by creating an
ignition voltage on circuit BRN/BLU. When ignition
voltage is energized by the PCM, the TCC solenoid stops
converter signal oil from exhausting. This causes
converter signal oil pressure to increase and move the
TCC valve. The TCC solenoid will deenergize when the
PCM no longer provides ignition voltage. When the TCC
solenoid is deenergized, it will exhaust fluid and release
the TCC.
This DTC detects low torque converter slip when the TCC
is commanded ªoffº. This is a type ªBº DTC.
Conditions For Setting The DTC
The following conditions occur once per TCC cycle, three
consecutive times:

No TPS DTCs P0122 or P0123.

No OSS DTCs P0722 or P0723.

No TCC solenoid DTC P1860.

TP angle is greater than 20%.

Engine speed is greater than 500 rpm and less than
3,000 rpm.

Engine vacuum is between 0 and 70 kPa.

Commanded gear is not 1st.

Gear range is D4.

TCC is commanded ªoffº.

No TCC Stuck off DTC P1870.
TCC slip speed is between ±20 and 40 rpm for 2
seconds.

Vehicle speed is greater than 25 km/h (15 mph) and
less than 120 km/h (75 mph).

Speed ratio is greater than 0.9 and less than 2.0.
Action Taken When The DTC Sets

For lamp illuminate refer to DTC type definition (type
B).

Inhibit TCC engagement.
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.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±57
Diagnostic Aids

If the TCC is mechanically stuck ªonº with the parking
brake applied and any gear range selected, the TCC
fluid will mechanically apply the TCC, possibly
causing an engine stall.
Test Description
The number below refers to the step number on the
diagnostic chart:
3. This test checks the mechanical state of the TCC.
(When the PCM commands the TCC solenoid ªoffº,
the slip speed should increase).
DTC P0742 Torque Converter Clutch (TCC) System Stuck On
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. Using the scan tool, verify the ªTP Sensorº operation.
Are the ªTP Sensorº values within 0.6 ± 5.0 volts?
Go to Step 3
Go to Diagnostic
Aids
3Drive the vehicle in the D4 drive range in fourth gear under steady
acceleration, with a TP angle greater than 20%.
Does the scan tool display ªTCC Slip Speedº between ±30 and
+30 rpm, while the displayed TCC solenoid state is ªoffº?
Go to Step 4
Go to Diagnostic
Aids
4The TCC is mechanically stuck ªonº. Check the following items:

Clogged exhaust orifice in the TCC solenoid.

Converter clutch apply valve stuck in the apply position.

Misaligned or damaged valve body gasket.

Restricted release passage.
Was a problem found and corrected?
Go to Step 5Ð
51. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
TCC slip speed must be between 200 and 2,500 rpm for 4
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±58
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0748 Pressure Control Solenoid (PCS) (Force Motor) Circuit Electrical
D07R200009
Circuit Description
The PCS is a PCM±controlled device used to regulate
transmission line pressure. The PCM compares TPS
voltage, engine rpm, and other inputs to determine the
line pressure appropriate for a given load. The PCM will
regulate the pressure by applying a varying amperage to
the PCS. The applied amperage can vary from 70 to 1060
milliampere (mA), and is monitored by the PCM.
This DTC detects a continuous open or short to ground in
the PCS circuit or the PCS. This is a type ªCº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

The PCM detects that the different between
commanded and actual current is 200 milliampere
(mA) for over 1 second.

Engine speed is greater than 300 rpm.
Action Taken When the DTC Sets

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

Maximum line pressure.

The PCM will illuminate the CHECK TRANS Lamp.

Turn Force Motor OFF (Durability).
Conditions For Clearing The DTC/CHECK
TRANS Lamp

The PCM will turn ªoffº the CHECK TRANS Lamp
after three consecutive ignition cycles without a
failure reported.
The DTC can be cleared from PCM history by using a
scan tool.

The DTC will be cleared from memory 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 at the transmission 4±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.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
2. This test checks the ability of the PCM to command
the PCS.
3. This test checks the PCS and internal wiring harness
for incorrect resistance.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±59
DTC P0748 Pressure Control Solenoid (PCS) (Force Motor) Circuit Electrical
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
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 ªFailure
Recordsº for reference, as data will be lost when the ªClear Infoº
function is used.
3. Record the DTC ªFailure Recordsº.
4. While the engine is operating, put the transmission in Park.
5. Using the scan tool, apply 70 through 1060 milliampere (mA)
while observing ªPC Ref. Currentº and ªPC Act. Currentº.
Is the ªPC Act. Currentº reading always within 160 mA?
Go to Diagnostic
Aids
Go to Step 3
31. Turn the ignition ªoffº.
2. Disconnect the transmission 4±way connector E±40.
3. Using the J39200 DVOM, measure the resistance between
terminals E40±2(B) and E40±4(C).
Is the resistance within 3±7 ohms?
Go to Step 7Go to Step 4
41. Remove the transmission oil pan. Refer to Solenoid (Adapter
Case Valve Body) in Automatic Transmission (4L30±E)
section.
2. Disconnect the internal wiring harness at the PCS.
3. Measure the resistance of the PCS.
Is the resistance within 3±7 ohms?
Go to Step 6Go to Step 5
5Replace the PCS.
Is the replacement complete?
Go to Step 10Ð
6Repair the internal wiring harness for an open.
Is the repair complete?
Go to Step 10Ð
7Inspect/repair circuits VIO/WHT and VIO/RED.
Was a problem found?
Go to Step 10Go to Step 8
8Inspect/repair circuits VIO/WHT and VIO/RED for a short to
ground or poor connections.
Was a problem found?
Go to Step 10Go to Step 9
9Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 10Ð
101. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:
The PCS duty cycle is not at its electrical high or low limit.
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±60
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0751 Shift Solenoid A Performance (Stuck Off)
D07RT011
Circuit Description
The shift solenoid A is used to control fluid flow acting on
the 1±2 and 3±4 shift valves. The solenoid is a normally
close exhaust valve that is used with the shift solenoid B
to allow four different shifting combinations.
The DTC detects when there is only a 1±1±4±4 shift
pattern depending on the state of the mechanical failure
instead of a 1±2±3±4 shift pattern. This is a type ªBº DTC.
Conditions For Setting The DTC

No ETC DTCs.

No OSS DTCs P0722 or P0723.

No TCC solenoid DTCs P0742, P1860, P1870.

No shift solenoid A DTC P0753.

No shift solenoid B DTC P0758.

Gear range is D4.

Transmission temperature is between 20
and 130
C
(68
and 266
F).

Output speed is greater than 375 rpm.

No range code P0705, P0706.

No torque code (to be confirmed).

Engine run for more 0 seconds and not influed cut-off
(to be confirmed).
All the above conditions have been met and the
combination of conditions 1, 2 occur two consecutive
times.
Condition 1:

2nd gear is commanded for . 1 second.

40 3 Engine Torque 3 400 N´m

Speed ratio . 0.6

Throttle position . 10 %

800 3 TCC Slip 3 4000 rpm

2.75 3 Modeled Ratio 3 3.2 for 1 second.
Condition 2:

3rd gear is commanded for . 1 second.

40 3 Engine Torque 3 400 N´m

Throttle position . 10 %

±8000 3 TCC Slip 3 8000 rpm

Speed ratio . 0.45

0.62 3 Modeled Ratio 3 0.92 for 3 second.
Action Taken When the DTC Sets

Maximum line pressure.

For lamp illuminate refer to
DTC type definition (type
B).

Turn Force Motor OFF.
Conditions For Clearing The 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

Verify that the transmission meets the specifications
in the 4L30±E shift speed chart.

Other internal transmission failures may cause more
than one shift to occur.