Last Modified: 11-29-2007 1.6 C
Service Category: Drivetrain Section: Automatic Transmission/Transaxle
Model Year: 2008 Model: Sequoia Doc ID: RM000002IR000IX
Title: A750F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

P2772

Four Wheel Drive (4WD) Low Switch Circuit Range / Performance

DESCRIPTION

The ECM detects the signal from the transfer 4L position switch.

This DTC indicates that the transfer 4L position switch remains on.

DTC No.

DTC Detection Condition

Trouble Area

P2772

Transfer 4L position switch remains ON while vehicle is running under following conditions for 1.8 seconds or more (1-trip detection logic)

(a) Output shaft speed between 1000 and 3000 rpm

(b) Transfer position switch is in 4H
  • Short in transfer 4L position switch circuit
  • 4WD control ECU
  • ECM

MONITOR DESCRIPTION

The ECM monitors the transfer-case 4L position switch to determine when the transfer-case 4L gears are engaged. If the transfer-case 4L gears remain engaged under the following conditions, the ECM will conclude that there is a malfunction of the 4L position switch, illuminate the MIL and store the DTC:

  • The 4L switch indicates that the 4L transfer-case gears are engaged.
  • The transfer-case shifter is in the "4H" position.
  • The transfer-case output shaft rpm is between 1000 and 3000 rpm.
  • The specified time period has elapsed.

MONITOR STRATEGY

Related DTCs

P2772: Transfer 4L position switch/ON malfunction

Required sensors/Components

Transfer 4L position switch

Frequency of operation

Continuous

Duration

ON malfunction (A): 1.8 seconds

ON malfunction (B): 0.5 seconds

MIL operation

1 driving cycle

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

Output speed sensor circuit

Not circuit malfunction

Vehicle speed sensor circuit

Not circuit malfunction

Transfer neutral position switch

OFF

ON Malfunction (A)

Output speed (Transfer output speed)

1000 rpm or more, and less than 3000 rpm

ON Malfunction (B)

Output speed (Transfer output speed)

143 rpm or more

TYPICAL MALFUNCTION THRESHOLDS

Both of the following conditions are met: ON malfunction (A) and (B)

ON Malfunction (A)

4L switch

ON

ON Malfunction (B)

Actual transfer gear ratio

Transfer input speed/Transfer output speed

0.9 or more, and less than 1.1

WIRING DIAGRAM

Refer to DTC P0818 A750F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: DESCRIPTION (2008 Sequoia)+ .

INSPECTION PROCEDURE

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - BODY GROUND)

(a) Disconnect the A28 4WD control ECU connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A28-21 (L4) - Body ground

Always

10 kΩ or higher

Result

Result

Proceed to

NG

A

OK

B
A

2.

CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - ECM)

(a) Disconnect the A27 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A27-21 (L4) - Body ground

Always

10 kΩ or higher

Result

Result

Proceed to

OK

A

NG

B
A