- Short in transfer L4 position switch circuit
- Four wheel drive control ECU
- ECM
| Last Modified: 11-27-2007 | 1.6 C | |
| Service Category: Drivetrain | Section: Automatic Transmission/Transaxle | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000002IR000HX |
| Title: AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: DESCRIPTION (2008 LX570) | ||
|
DTC |
P2772 |
Four Wheel Drive (4WD) Low Switch Circuit Range / Performance |
DESCRIPTION
The ECM detects the signal from the transfer L4 position switch.
This DTC indicates that the transfer L4 position switch remains on.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P2772 |
The transfer L4 position switch remains on while the vehicle is running under the following conditions for 1.8 sec. or more (1-trip detection logic). (a) The output shaft speed is between 1000 and 3000 rpm. (b) The transfer position switch is in H4. |
|
MONITOR DESCRIPTION
The ECM monitors the transfer-case L4 position switch to determine when the transfer-case L4 gears are engaged. If the transfer-case L4 gears remain engaged under the following conditions, the ECM will conclude that there is a malfunction of the L4 position switch, illuminate the MIL and store the DTC:
- The L4 switch indicates that the L4 transfer-case gears are engaged.
- The transfer-case shifter is in the "H4" 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 L4 position switch/ON malfunction |
|
Required sensors/Components |
Transfer L4 position switch |
|
Frequency of operation |
Continuous |
|
Duration |
ON malfunction (A): 1.8 sec. ON malfunction (B): 0.5 sec. |
|
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 position |
Not neutral |
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
When both conditions below are met: ON malfunction (A) and (B)
ON malfunction (A)
|
L4 switch |
ON |
ON malfunction (B)
|
Actual transfer gear ratio Transfer input speed/Transfer output speed (NO/NOtf) |
0.9 or more, and less than 1.1 |
WIRING DIAGRAM
Refer to DTC P0818
.
INSPECTION PROCEDURE
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (FOUR WHEEL DRIVE CONTROL ECU - BODY GROUND) |
|
(a) Disconnect the A27 four wheel drive control ECU 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 |
|
|
3. |
CHECK HARNESS AND CONNECTOR (FOUR WHEEL DRIVE CONTROL ECU - ECM) |
|
(a) Disconnect the A38 ECM connector. |
(b) Disconnect the A27 four wheel drive control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A38-21 (L4) - Body ground |
Always |
10 kΩ or higher |
|
|
|