P2772

A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P2772: Four Wheel Drive (4WD) Low Switch Circuit Range / Performance

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.






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





TYPICAL ENABLING CONDITIONS

All





ON Malfunction (A)





ON Malfunction (B)





TYPICAL MALFUNCTION THRESHOLDS

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

ON Malfunction (A)





ON Malfunction (B)





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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




(a) Disconnect the A25 4WD control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






Result





B -- GO TO TOUCH SELECT 2-4 AND HIGH-LOW SYSTEM
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - ECM)




(a) Disconnect the A24 ECM connector.
(b) Disconnect the A25 4WD control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






Result





B -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE ECM