P0748

DTC P0748: Line Pressure Linear Solenoid Valve System

SOLENOID VALVE SYSTEM CIRCUIT
Refer to DTC P0743. P0743

DESCRIPTIONS OF MONITOR METHODS
^ With the ignition switch ON, an abnormal value equivalent to open or short circuit is detected in the solenoid control current for 5 seconds.

MONITOR EXECUTION
^ Continuous

MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
^ Not applicable

Sensor (The sensor below is determined to be normal)
^ Not applicable

LOGIC FLOW CHARTS (Monitor Sequence)

Logic Flow Charts (Monitor Sequence):

DTC SET CONDITIONS

Check Conditions [Circuit continuity ground]
^ Voltage of battery: 2 volts or more.

Judgement Criteria [Circuit continuity ground]
^ Ground short judgement: abnormal. (5 seconds)

Check Conditions [Circuit continuity open]
^ Voltage of battery: 2 volts or more.
^ Ground short judgement: normal.

Judgement Criteria [Circuit continuity open]
^ Open short judgement: abnormal. (5 seconds)

OBD-II DRIVE CYCLE PATTERN
Start the engine, and keep the vehicle stopped in "P" range for 5 seconds.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the line pressure linear solenoid valve system circuit
^ Damaged harness or connector
^ Malfunction of the TCM
^ Malfunction of the line pressure linear solenoid valve (valve body assembly)

DIAGNOSIS

STEP 1. Check the TCM terminal voltage.
[C-37 TCM connector (vehicle side, connected)]

Measure the voltage between the terminal No. 40 and body ground.

^ While driving: 300 Hz
^ Other than above: 0 V

Q:Is the check result normal?
YES: Go to Step 5.
NO: Go to Step 2.

STEP 2. Check between the TCM connector and A/T control solenoid valve assembly connector.
Check for continuity between C-37 TCM connector and B-111 A/T control solenoid valve assembly connector.

^ Between C-37 terminal No. 40 and B-111 terminal No. 9: Continuity exists.

When the continuity check result is OK, check that the wiring harness is not shorted to the body and other wiring harness.

Q:Is the check result normal?
YES: Go to Step 3.
NO: Repair or replace the failure section.

STEP 3. Check the line pressure linear solenoid.

Q:Is the check result normal?
YES: Go to Step 6.
NO: Go to Step 4.

STEP 4. Check between the A/T control solenoid valve assembly connector and the line pressure linear solenoid valve connector.
Check for continuity between the A/T control solenoid valve assembly connector terminals and the line pressure linear solenoid valve connector terminals.

^ Between C-111 terminal No. 9 and line pressure linear solenoid valve: Continuity exists.

Q:Is the check result satisfactory?
YES: Replace the valve body assembly.
NO: Repair or replace the failure section.

STEP 5. Check the TCM and A/T control solenoid valve assembly connector pin terminals and the connection status.

Q:Is the check result normal?
YES: Go to Step 7.
NO: Repair or replace the failure section.

STEP 6. Check the TCM and A/T control solenoid valve assembly connector pin terminals and the connection status.

Q:Is the check result normal?
YES: Replace the TCM.
NO: Repair or replace the failure section.

STEP 7. Erase the DTC code, and drive the vehicle for a while.
Check that the normal code is displayed.

Q:Is the check result normal?
YES: The procedure is complete.
NO: Return to START.