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Isuzu KB P190. Manual - part 972

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–102

Step Action

Yes

Connect Tech 2 to the DLC.

Turn on the ignition, with the engine off.

N O T E

Before clearing the DTC, use the Tech

2 Freeze

Frame/Failure Record to record the transmission
parameters at the time the DTC set. Using Tech 2 to clear
the DTC(s) erases the Freeze Frame/Failure Record
records from the TCM.

On Tech 2 select:
Transmission / Automatic Transmission / Diagnostic
Trouble Codes / Freeze Frame.

Select the relevant DTC and note the parameters at the time of
the DTC setting.

On Tech 2 select:
Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.

Follow the instructions on Tech 2 and clear the DTCs.

On Tech 2 select:
Transmission / Automatic Transmission / Miscellaneous
Tests / Shift Solenoid B.

With Tech 2 command the shift solenoid B ON and OFF three
times.

On Tech 2 select:
Data Display / 2-3 Shift Data.

Does Tech 2 display the Shift Solenoid B Circuit as Okay?

Check for an

intermittent fault in

the circuit, refer to

8A Electrical-Body

and Chassis

Go to Step 3

Turn off the ignition.

Disconnect connector E-95 from the transmission.

N O T E

Additional DTCs may set.

Install Tool No. J 44152 Jumper Harness (20 pins) on to the
harness connector E-95.

Turn on the ignition, with the engine off.

Using a test lamp, probe between connector E-95 pin 3 and a
known ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 4

Install Tool No. J44152 on to the transmission connector E-95.

Using a multimeter set to measure resistance, probe across
transmission connector E-95 pins 10 and 3.

Does the multimeter display less than 20

Ω?

Go to Step 5

Go to Step 7

Remove Tool No. J44152 from the transmission.

Gain access to the 2-3 SS and the control valve body wiring
harness, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.

Disconnect the internal connector from the 2-3 SS.

Using a multimeter set to measure resistance, probe across the
2-3 SS pins.

Does the multimeter display less than 20

Ω?

Replace the 2-3 SS,

refer to

7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing.

Go to Step 8

Replace the control

valve body wiring

harness, refer to

7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing

Go to Step 8

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–103

Step Action

Yes

Using a multimeter, test between E-95 pin 3 and C-96 pin 30 for a
short to voltage.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing

Did you complete the replacement?

Go to Step 8

—

Perform the following procedure to verify the repair:

On Tech 2 select:
Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.

Follow the instructions on Tech 2 and clear any DTCs.

On Tech 2 select:
Data Display / 2-3 Shift Data.

Drive the vehicle in D4 and ensure the following conditions are
met::

•

The TCM commands the Shift Solenoid B On and the
Shift Solenoid B Circuit status parameter displays Okay.

•

The TCM commands the Shift Solenoid B Off and the
Shift Solenoid B Circuit status parameter displays Okay.

•

All conditions are met for 5 seconds.

On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.

Has DTC P0977 set?

Go to Step 2

Go to Step 9

On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.

Does Tech 2 display any DTCs you have not diagnosed?

Refer to

4.8 Diagnostic

Trouble Code List

System OK

When all diagnosis and repairs are completed, check the system for correct operation.

4.32 DTC P1810, P1815 and P1816 –

Transmission Fluid Pressure Position
Switch

DTC Description

This diagnostic procedure supports the following DTCs:

•

DTC P1810 Transmission Fluid Pressure (TFP) Position Switch Circuit.

•

DTC P1815 Transmission Fluid Pressure (TFP) Valve Position Switch – Start in Wrong Range.

•

DTC P1816 Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Park/Neutral (P/N) with Drive Ratio.

Circuit Description

The automatic transmission fluid pressure (TFP) manual valve position switch consists of five pressure switches
(two normally-closed and three normally-open) and a transmission fluid temperature (TFT) sensor combined into one unit.
The combined unit mounts on the valve body. The transmission control module (TCM) supplies ignition voltage for each
range signal. By grounding one or more of these circuits through various combinations of the pressure switches, the
TCM detects which manual valve position you select. The TCM compares the actual voltage combination of the switches
to a TFP manual valve position switch combination chart stored in memory.

The TFP manual valve position switch cannot distinguish between park and neutral because the monitored valve body
pressures are identical. With the engine off and the ignition switch on, the TFP manual valve position switch indicates

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–104

park/neutral. Disconnecting connector E-95 from the transmission removes the ground potential for the three range
signals to the TCM. In this case, with the engine off, and the ignition switch on, D2 will be indicated.

When the TCM detects an invalid state of the TFP manual valve position switch circuit by deciphering the TFP manual
valve position switch inputs, then either DTC P1810, P1815 or P1816 sets. All theses DTCs are a type B DTC.

Refer to 2

Wiring Diagrams and Connector Chart to aid in diagnosis.

Conditions for Running the DTC

DTC P1810

•

The system voltage is 8 – 18 V.

•

The engine speed is greater than 500 r.p.m. for 5 seconds.

DTC P1815

•

No DTCs P0722 or P0723.

•

The system voltage is 8 – 18 V.

•

The engine speed is less than 50 r.p.m., then 50 – 650 r.p.m. for 0.75 seconds, then greater than 650 r.p.m. for
5 seconds.

•

Output shaft speed less than 250 r.p.m.

DTC P1816

•

No DTCs P0722 or P0723.

•

The system voltage is 8 – 18 V.

•

The engine speed is less than 50 r.p.m., then 50 – 650 r.p.m. for 0.75 seconds, then greater than 650 r.p.m. for
5 seconds.

•

Output shaft speed less than 250 r.p.m.

Conditions for Setting the DTC

DTC P1810

DTC P1810 sets when the TCM detects an invalid TFP manual valve position switch state for 60 seconds.

DTC P1815

DTC P1815 sets when the TCM detects D2 only, TFP manual valve position switch state after engine start for 7 seconds.

DTC P1816

DTC P1816 sets when the TCM detects one of the following conditions for 13 seconds:

•

park/neutral indicated with a 1st gear ratio,

•

park/neutral indicated with a 2nd gear ratio,

•

park/neutral indicated with a 3rd gear ratio, or

•

park/neutral indicated with a 4th gear ratio.

Action Taken When the DTC Sets

•

The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the conditions for
setting the DTC are met.

•

The TCM commands maximum line pressure.

•

The TCM freezes transmission adaptive functions.

•

The TCM inhibits TCC engagement.

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–105

•

The TCM commands 4th gear.

•

At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.

•

At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.

•

The TCM stores the DTC in TCM history during the second consecutive trip in which the conditions for setting the
DTC are met.

Conditions for Clearing the DTC

•

The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.

•

Tech 2 can clear the DTC.

•

The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.

•

The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.

Diagnostic Aids

•

Refer to the 5.3

Transmission Fluid Pressure Manual Valve Position Switch Logic for the normal range signals

and the invalid combinations. On the table, LOW is 0 V, HI is ignition voltage.

•

Sediment in the valve body may cause improper operation of the TFP manual valve position switch. If the presence
of sediment is suspected, clean the valve body and replace the TFP manual valve position switch.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

Checks the indicated range signal to the selected manual valve position.

4-5 Checks for correct voltage from the TCM to the transmission inline 20-way connector.

Checks if there is a short between any of the signal circuits.

DTC P1810, P1815 and P1816 Diagnostic Table

Step Action

Yes

Has the Diagnostic System Check been performed?

Go to Step 2

Refer to

4.7 Diagnostic

System Check

Inspect for correct transmission fluid level, refer to 7C4 Automatic
Transmission – 4L60E – On-vehicle Servicing.

Did you perform the fluid checking procedure?

Go to Step 3

Refer to

7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing

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