Isuzu Trooper 1999 Workshop Manual page 1510

Conditions For Clearing The DTC/CHECK
TRANS Lamp
f The PCM will turn "off" the CHECK TRANS Lamp
after three consecutive ignition cycles without a
failure reported.
f The DTC can be cleared from PCM memory by using
a scan tool.
f The DTC can also be cleared from memory when the
vehicle has made 40 warmup cycles without a failure
reported.
f 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.
DTC P0730 Transmission Incorrect Gear Ratio
Step
1 Were you sent here from the "On–Board Diagnostic (OBD)
System Check"?
2 Visually inspect the transmission cooling system for fluid leaks.
f 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?
3 Refer to Checking Transmission Fluid Level and Condition in
Automatic Transmission (4L30–E) section.
Has transmission fluid checking procedure been performed?
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 1, 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?
TRANSMISSION CONTROL SYSTEM (4L30–E)
Diagnostic Aids
f Check for intermittent output speed sensor circuit
f Check for possible incorrect calibration. (PCM part
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This step checks for possible low fluid level causing
4. This step checks for correct gear ratios for
5. This step checks for low line pressure.
Action
problems.
No., tire specification, and rear axle ratio)
slipping resulting in an undefined gear ratio.
commanded gears.
Yes
Go to Step 2
Go to Step 7
Go to Step 4
Refer to
Diagnostic Aids
7A1–57
No
Go to OBD
System Check
Refer to
Driveability and
Emission in
Engine section
Go to Step 3
Go to Checking
Transmission
Fluid Level and
Condition in
Automatic
Transmission
(4L30–E) section
Go to Step 5