P1772

P1772 Low Coast Brake Solenoid

Description

Low coast brake solenoid valve is turned "ON" or "OFF" by the TCM in response to signals sent from the transmission range switch, output speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be shifted to the optimum position.

SDT Reference Value in Data List Mode

[Main Power Supply and Ground Circuit Check] Shift Mechanism Shift Mechanism





On Board Diagnosis Logic

- This is an OBD-II self-diagnostic item.
- Diagnostic trouble code "P1772" with SDT or 7th judgment flicker without SDT is detected when TCM detects an improper voltage drop when it tries to operate the solenoid valve.

Possible Cause

- Harness or connectors
(The solenoid circuit is open or shorted.)
- Low coast brake solenoid valve

DTC Confirmation Procedure

NOTE:

If "DTC Confirmation Procedure" has been previously performed, always turn ignition switch "OFF" and wait at least 10 seconds before performing the next test.

After the repair, perform the following procedure to confirm the malfunction is eliminated.

with SDT

1 Turn ignition switch "ON". (Do not start engine.)
2 Select "Data list" mode for "Engine / Powertrain" with SDT.
3 Start engine.
4 Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
SLCT LVR POSI: "1" or "2"
GEAR: "1st" or "2nd" (LC/B ON/OFF)
5 If DTC is detected, go to "Diagnosis Procedure".

with GST

Follow the procedure "WITH SDT".

Diagnosis Procedure

1. CHECK INPUT SIGNAL

With SDT
1 Turn ignition switch ON.
2 Select "SELECTION FROM MENU" in "Data list" mode for "AT" with SDT.
3 Start the engine.
4 Read out the value of "ON OFF SOL" while driving.

OK or NG
OK
GO TO 4.
NG
GO TO 2.

2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT

Check TCM power supply and ground circuit. Refer to Main Power Supply and Ground Circuit Check.

OK or NG
OK
GO TO 3.
NG
Repair or replace damaged parts.

3. DETECT MALFUNCTIONING ITEM

Check the following.
- The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.

OK or NG
OK
Replace the control valve with TCM. Refer to [Control Valve with TCM: Removal and Installation] Service and Repair.
NG
Repair or replace damaged parts.

4. CHECK DTC

Perform "DTC Confirmation Procedure".
- Refer to "DTC Confirmation Procedure".

OK or NG
OK
INSPECTION END
NG
GO TO 2.