Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 436

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

D

The PCM will illuminate the CHECK TRANS Lamp.

D

Turn force motor OFF.

Conditions For Clearing The DTC/CHECK
TRANS Lamp

D

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

D

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

D

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

D

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

Diagnostic Aids

D

Check for intermittent output speed sensor circuit
problems.

D

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 

Step

Action

Yes

No

1

Were you sent here from the “On–Board Diagnostic (OBD)
System Check”?

Go to 

Step 2

Go to 

OBD

System Check

Refer to

Driveability and

Emission in

Engine section

2

Visually inspect the transmission cooling system for fluid leaks.

D

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 7

Go to 

Step 3

3

Refer 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

4

1. Install the scan tool.
2. Turn the ignition switch to the “on” position.
3. Engine not running.

NOTE: Before clearing DTC(s) use the scan tool to record the
“Failure Records” for reference, as data will be lost when the “Clear
Info” 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 Aids

Go to 

Step 5

TRANSMISSION CONTROL SYSTEM (4L30–E)

7A1–55

DTC P0730 Gear Error Without Input Speed  (Cont’d)

Step

No

Yes

Action

5

Perform line pressure check.

D

Refer to 

Line Pressure Test in Automatic Transmission

(4L30–E) section.

Was condition found and corrected?

Go to 

Step 7

Go to 

Step 6

6

Check for possible clutch slippage.

D

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 7

—

7

1. After the repair is complete, use the scan tool to select “DTC”,

then “Clear info” function.

2. Operate the vehicle under the following conditions:

D

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 “off”.  This is a type “B” DTC.

Conditions For Setting The DTC

The following conditions occur once per TCC cycle, three
consecutive times:

D

No TPS DTCs P0122 or P0123.

D

No OSS DTCs P0722 or P0723.

D

No TCC solenoid DTC P1860.

D

TP angle is greater than 20%.

D

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

D

Engine vacuum is between 0 and 70 kPa.

D

Commanded gear is not 1st.

D

Gear range is D4.

D

TCC is commanded “off”.

D

No TCC Stuck off DTC P1870.

D

TCC slip speed is between –20 and 40 rpm for 2
seconds.

D

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

D

Speed ratio is greater than 0.9 and less than 2.0.

Action Taken When The DTC Sets

D

For lamp illuminate refer to 

DTC type definition (type

B).

D

Inhibit TCC engagement.

Conditions For Clearing The MIL/DTC

D

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

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.

TRANSMISSION CONTROL SYSTEM (4L30–E)

7A1–57

Diagnostic Aids

D

If the TCC is mechanically stuck “on” 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 “off”,
the slip speed should increase).

DTC P0742 Torque Converter Clutch (TCC) System Stuck On 

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

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”.
4. Using the scan tool, verify the “TP Sensor” operation.

Are the “TP Sensor” values within 0.6 – 5.0 volts?

Go to 

Step 3

Go to 

Diagnostic
Aids

3

Drive 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 “TCC Slip Speed” between –30 and
+30 rpm, while the displayed TCC solenoid state is “off”?

Go to 

Step 4

Go to 

Diagnostic
Aids

4

The TCC is mechanically stuck “on”.  Check the following items:

D

Clogged exhaust orifice in the TCC solenoid.

D

Converter clutch apply valve stuck in the apply position.

D

Misaligned or damaged valve body gasket.

D

Restricted release passage.

Was a problem found and corrected?

Go to 

Step 5

—

5

1. After the repair is complete, use the scan tool to select “DTC”,

then “Clear Info” 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 “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