ISUZU AXIOM 2002 Service Repair Manual

7A1±74
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0758 Shift Solenoid B Electrical (Cont'd)
StepNo Ye s Action
11Check every connection of the PCM.
Was a problem found and corrected?
Go to Step 22Go to Step 12
121. Connect the E-34 (BLUE) and E-35 (RED) PCM connectors to
the PCM.
2. Turn the ignition ªonº, the engine ªonº.
3. Repeat Step 3.
Does the scan tool display DTC P0758 at 3rd gear?
Go to Step 21
Go to Diagnostic
Aids
13The wiring harness between PCM connector terminal
E35±31 and transmission main case terminal E42±6(A) is shorted
to voltage.
Was a problem found and corrected?
Go to Step 22Ð
14The PCM internal terminal E35±31 is shorted to voltage.
Replace the PCM. Refer to
Powertrain Control Module (PCM) in
Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 22Ð
15The wiring harness between PCM connector and transmission
main case 7-way connector is shorted.
Was a problem found and corrected?
Go to Step 22Ð
16The shift solenoid B is faulty, or the internal wiring harness from
the shift solenoid B is shorted.
Was a problem found and corrected?
Go to Step 22Ð
17The wiring harness between PCM connector terminal
E35±31 and transmission main case connector terminal
E42±6(A) is shorted to ground.
Was a problem found and corrected?
Go to Step 22Ð
18The wiring harness between PCM connector terminal E35±43
and transmission main case connector terminal E42±2(D) is
shorted to ground.
Was a problem found and corrected?
Go to Step 22Ð
19The wiring harness between PCM connector terminal E35±31
and transmission main case connector terminal E42±6(A), or
between PCM connector terminal E35±43 and main case
connector terminal E42±2(D) is open.
Was a problem found and corrected?
Go to Step 22Ð
20The internal wiring harness from the shift solenoid B is open, or
the shift solenoid B is faulty.
Was a problem found and corrected?
Go to Step 22Ð
21Replace the PCM.
Is the replacement complete?
Go to Step 22Ð
221. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and operate the vehicle under the
following conditions:

The shift solenoid B is commanded ªonº and voltage drops to
zero.

The shift solenoid B is commanded ªoffº and voltage
increases to B+.
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±75
DTC P1850 Brake Band Apply Solenoid Malfunction
D07R200010
Circuit Description

The brake band apply solenoid is a normally open
solenoid which controls the flow of fluid for brake band
application. The Powertrain Control Module (PCM)
uses Pulse Width Modulation (PWM) and changes
the duty cycle to control the solenoid. The PCM turns
the solenoid on (energized) and off (deenergized) at a
constant frequency. The length of time the solenoid is
energized during each on/off cycle is called the pulse
width. By varying or ªmodulatingº the pulse width, the
solenoid output pressure is changed. Since the
solenoid is normally open, increasing the pulse width
increases the duty cycle and decreases the output
pressure. PWM control provides smooth band
application without an accumulator. The band is only
applied in first and second gears.

In the event of an electrical failure (open), the
solenoid regulates at the maximum oil flow (0% duty
cycle).

The solenoid is activated by a current. This current is
produced by applying a voltage to one side (the High
side) and a ground to the other side (Low side).

The High Side Driver (HSD) is a circuit of the PCM
that acts as a switch between the solenoids and the
supply voltage. The High side of the solenoid is
permanently supplied with voltage. When the ignition
is off, the HSD is turned off.This DTC detects a continuous open or short to ground in
the brake band apply solenoid circuit or the brake band
apply solenoid. This is a type ªDº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

Ignition is ªonº, Engine ªrunº.

The PCM commands the solenoid ªonº and the
voltage remains high (B+), or the PCM commands
the solenoid ªoffº and the voltage remains low (zero
volts).

All conditions met in 1.34 ~ 1.56 seconds.
Action Taken When The DTC Sets

Inhibit brake band apply solenoid.

The PCM will not illuminate the Malfunction Indicator
Lamp (MIL).
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 ªoffº
long enough to power down the PCM.

7A1±76
TRANSMISSION CONTROL SYSTEM (4L30±E)
Diagnostic Aids

Inspect the wiring for poor electrical connection at the
PCM and at the transmission 7±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:
3. This test checks for power to the brake band apply
solenoid from the ignition through the PCM.
4. This test checks the resistance of the transmission
internal wiring harness and brake band apply
solenoid.
5. This test checks the ability of the PCM and wiring to
control the ground circuit.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±77
DTC P1850 Brake Band Apply Solenoid Malfunction
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 ªonº, 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.
Were DTCs P0753, P0758 set?
Go to Step 3Go to Step 4
3Using the J39200 DVOM, back probe between PCM connector
terminals E35±43 and E35±1.
Is the voltage between 10 to 12 volts?
Go to Step 5Go to Step 6
41. Turn the ignition ªoffº.
2. Disconnect the E-34 (BLUE) and E-35 (RED) PCM connector.
3. Using the J39200 DVOM, measure the resistance between
PCM connector terminals E35±43 and E35±10.
Is the resistance within 10±12 ohms?
Go to Step 10Go to Step 11
5Using the J39200 DVOM, back probe between PCM connector
terminals E35±10 and E35±1.
Is the voltage between 10 to 12 volts?
Go to Step 19Go to Step 4
61. Turn the ignition ªoffº.
2. Disconnect the E-34 (BLUE) and E-35 (RED) PCM connector.
3. Using the J39200 DVOM, check continuity between PCM
terminal E35±43 and ground.
Is there a continuity?
Go to Step 7Go to Step 8
71. Disconnect the transmission main case connector E-42.
2. Using the J39200 DVOM, check continuity between the
terminal E42±7(B) and ground.
Is there continuity?
Go to Step 13Go to Step 14
81. Disconnect the E-34 (BLUE) and E-35 (RED) PCM Connector.
2. Using the J39200 DVOM, measure the resistance between
the PCM connector terminals E35±43 and E35±10.
Is the resistance within 10±12 ohms?
Go to Step 19Go to Step 9
91. Disconnect the transmission main case connector E-42.
2. Using the J39200 DVOM, measure the resistance between
the terminals E42±7(B) and E42±2(D).
Is the resistance within 10±12 ohms?
Go to Step 15Go to Step 16
10Using the J39200 DVOM, check continuity between PCM
terminal E35±10 and ground.
Is there continuity?
Go to Step 12Go to Step 19
111. Disconnect the transmission main case connector E-42.
2. Using the J39200 DVOM, measure the resistance between
the terminals E42-7(B) and E42-2(D).
Is the resistance within 10±12 ohms?
Go to Step 18Go to Step 16

7A1±78
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P1850 Brake Band Apply Solenoid Malfunction (Cont'd)
StepNo Ye s Action
121. Disconnect the transmission main case connector E-42.
2. Using the J39200 DVOM, check continuity between the
terminals E42±7(B) and ground.
Is there a continuity?
Go to Step 13Go to Step 17
13The brake band apply solenoid is faulty, or the internal wiring
harness from the brake band apply solenoid is shorted to ground.
Was a problem found and corrected?
Go to Step 20Ð
14The wiring harness between the PCM connector terminal E35±43
and the transmission main case connector terminal E42±2(D) is
shorted to ground.
Was a problem found and corrected?
Go to Step 20Ð
15The wiring harness between the PCM connector terminal E35±43
and the transmission main case connector terminal E42±2(D) is
open.
Was a problem found and corrected?
Go to Step 20Ð
16The brake band apply solenoid is faulty, or the internal wiring
harness from the brake band apply solenoid is open.
Was a problem found and corrected?
Go to Step 20Ð
17The wiring harness between the PCM connector terminal E35±10
and the transmission main case connector terminal E42±7(B) is
shorted to ground.
Was a problem found and corrected?
Go to Step 20Ð
18The wiring harness between the PCM connector terminal E35±10
and the transmission main case connector terminal E42±7(B) is
open.
Was a problem found and corrected?
Go to Step 20Ð
19Check every connection at the PCM.
If OK, replace the PCM. Refer to
Powertrain Control Module
(PCM) in Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 20Ð
201. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:

The brake band apply solenoid is commanded ªonº and the
volts drop to zero.

The brake band apply solenoid is commanded ªoffº and the
volts increase to B+.
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±79
DTC P1860 TCC PWM Solenoid Electrical
D07R200011
Circuit Description
The PCM allows current to flow through the solenoid coil
according to the duty cycle (percentage of ªonº and ªoffº
time). This current flow through the solenoid coil creates
a magnetic field that magnetizes the solid core. The
magnetized core attracts the check ball to seat against
spring pressure. This blocks the exhaust for the TCC
signal fluid and allows 2±3 drive fluid to feed to TCC signal
circuit.The TCC signal fluid pressure acts on the TCC
regulator valve to regulate line pressure and to apply fluid
pressure to the torque converter clutch shift control valve.
When the TCC shift valve is in the apply position,
regulated apply fluid pressure is directed through the TCC
valve to apply the torque converter clutch. The TCC
PWM solenoid is used in conjunction with the TCC PWM
solenoid to regulate fluid to the torque converter. The
TCC PWM solenoid is attached to the valve body within
the transmission.
This DTC detects a continuous open or short to ground or
ignition in the TCC circuit or the TCC PWM solenoid. This
is a type ªBº DTC.
Conditions For Setting The DTC

Battery voltage is between 10 and 16 volts.

No shift solenoid A DTCs P0751 or P0752 or P0753.

No shift solenoid B DTCs P0756 or P0757 or P0758.

Ignition is ªonº, Engine ªrunº.

The PCM commands the solenoid ªonº and the
voltage remains low (zero volts).

The PCM commands the solenoid ªoffº and the
voltage remains high (B+).

All conditions met for 0.875 ~ 1.25 seconds.
Action Taken When The DTC Sets

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

Inspect the wiring for poor electrical connections at
the PCM and at the transmission 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
:
3. This test checks for voltage to the solenoid.
4. This test checks the ability of the PCM and wiring to
control the ignition circuit.
9. This test checks the resistance of the TCC solenoid
and the internal wiring harness.

7A1±80
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P1860 TCC PWM Solenoid 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 ªonº, 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 theªClear Infoº function is used.
3. Record the DTC ªFreeze Frameº and ªFailure Recordsº.
Was DTC P1860 set?
Go to Step 3Go to Step 4
3Using the J39200 DVOM, back probe between PCM connector
terminals E35±51 and E35±33.
Is the voltage 0?
Go to Step 5Go to Step 6
41. Apply brake pedal and select transmission range ªDº.
2. Do a test drive, and increase the vehicle speed to TCC ªonº at
4th.
Does the scan tool display DTC P1860 at TCC ªONº?
Go to Step 9
Go to Diagnostic
Aids
51. Turn the ignition ªoffº.
2. Disconnect the E-35 (RED) PCM connector.
3. Using the J39200 DVOM, measure the resistance between
PCM connector terminals E35±51 and E35±33.
Is the resistance within 18 ± 20 ohms?
Go to Step 7Go to Step 8
6The wiring harness between PCM connector terminal E35±51
and transmission adapter case connector terminal E40±1(A) is
shorted to voltage.
Was a problem found and corrected?
Go to Step 15Go to Step 16
7Intermittent condition.
Check the wiring harness and terminals between PCM connector
J2 and transmission adapter case connector E±40.
Was a problem found and corrected?
Go to Step 15Go to Step 16
81. Disconnect the transmission adapter case connector E±40.
2. Using the J39200 DVOM, measure the resistance between
terminal E40±1(A) and ground.
Is the resistance within 18 ± 20 ohms?
Go to Step 13Go to Step 14
91. Turn the ignition ªoffº.
2. Disconnect the E-35 (RED) PCM connector.
3. Using the J39200 DVOM, measure the resistance between
terminals E35±51 and E35±33.
Is the resistance within 18 ± 20 ohms?
Go to Step 15Go to Step 10
101. Disconnect the transmission adapter case connector E±40.
2. Using the J39200 DVOM, measure the resistance between
terminal E40±1(A) and ground.
Is the resistance within 18±20 ohms?
Go to Step 11Go to Step 12
11The wiring harness between PCM connector E-35 and adapter
case connector E-40 is shorted to ground.
Was a problem found and corrected?
Go to Step 17Ð

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±81
DTC P1860 TCC PWM Solenoid Electrical (Cont'd)
StepNo Ye s Action
12The TCC solenoid is faulty, or the internal wiring harness from the
TCC solenoid is shorted to ground.
Was a problem found and corrected?
Go to Step 17Ð
13The wiring harness between PCM connector terminal E35±51
and adapter case terminal E40±1(A) is open.
Was a problem found and corrected?
Go to Step 17Ð
14The TCC solenoid is faulty, or the internal wiring harness from the
TCC solenoid is open.
Was a problem found and corrected?
Go to Step 17Ð
15Check every connection at the PCM.
If OK, replace the PCM. Refer to
Powertrain Control Module
(PCM) in Automatic Transmission (4L30±E) section.
Is the replacement complete?Go to Step 17Ð
16Check the PCM connector terminal E35±51, and transmission
adapter case connector terminal E40±1(A).
Was a problem found and corrected?
Go to Step 17Ð
171. After the repair is complete, use the scan tool to select ªDTCº,
then ªClear Infoº function and ensure the following conditions
are met:

The TCC solenoid is commanded ªonº and the volts increase
to B+.

The TCC solenoid is commanded ªoffº and the volts drop to
zero.
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±82
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P1870 Transmission Component Slipping (TCC Stuck Off)
D07R200008
Circuit Description
The PCM monitors the difference in engine speed and
transmission output speed. For example in D3 drive
range with the ECCC commanded, the engine speed
should closely match transmission output speed.
This DTC detects excessive TCC slip when the ECCC is
engaged. This is a type ªBº DTC.
Conditions For Setting The DTC
The following conditions are met for three TCC cycles
with reported excessive TCC slip conditions.

No OSS DTCs P0722 or P0723.

No shift solenoid A DTCs P0751 or P0752 or P0753.

No shift solenoid B DTCs P0756 or P0757 or P0758.

No TCC solenoid DTCs P0742 or P1860 or P1870.

Engine speed is between 1,000 and 3,500 rpm for 0.5
seconds.

Gear range is D4.

13% < TPS < 99%

50 < Engine Torque < 300 N´m

TFT is between 20
and 150
C (68
and 302
F).

TCC slip speed is between 250 rpm and 800 rpm for 3
times 7 seconds.

Vehicle speed is between 25 km/h (15 mph) and 225
km/h (158 mph).

Speed ratio is between 0.6 and 0.95.

ECCC is ªONº.
Low (0.8) < TCC Capacity < hi (0.99) for 5 seconds
Action Taken When The DTC Sets

Only stored in memory.

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 exist and the ignition is cycled ªoffº
long enough to power down the PCM.
Diagnostic Aids

Range switch malfunction could set a DTC P1870.

A mechanical failure of the shift solenoids, TCC
solenoid, or TCC PWM solenoid could set a DTC
P1870.

Internal transmission failures may set a DTC P1870.

An intermittent or incorrect engine speed signal may
set a DTC P1870.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±83
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
2. This test checks the indicated range signal to the
actual selected range. A faulty switch could set a
DTC P1870.
3. This test checks the torque converter for slippage
while in a commanded lockup state.Range Switch Logic Table
RangeRange Switch Ping
PositionABCP(G)
ParkONOFFOFFON
ReverseONONOFFOFF
NeutralOFFONOFFON
D4OFFONONOFF
D3ONONONON
2ONOFFONOFF
LOFFOFFONON
IllegalOFFOFFOFFOFF
IllegalOFFOFFOFFON
DTC P1870 Transmission Component Slipping (TCC Stuck Off)
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. Apply the brake pedal.
5. Select each transmission range: DL, D2, D3, D4, N, R, and P.
Does each selected transmission range match the scan tool ªTR
Switchº display?
Go to Step 3
Go to ªRange
Switch Logic
Tableº
3Drive the vehicle in 4th gear while the TCC is engaged.
At any time is the ªTCC Slip Speedº greater than 130 rpm for 8
seconds while the TCC is engaged?
Go to System
Diagnosis ChartsGo to Diagnostic
Aids