| Last Modified: 11-29-2007 | 1.6 U | |
| Service Category: Drivetrain | Section: Automatic Transmission/Transaxle | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000000O8L08RX |
| Title: AB60E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART (2008 Sequoia) | ||
FAIL-SAFE CHART
1. Fail-safe
This function minimizes the loss of the ECT functions when a malfunction occurs in a sensor or solenoid.
2. Fail-safe control list
|
Malfunctioning Part |
Function |
|---|---|
|
DTC P0717: Input Speed Sensor NT |
During an input speed sensor malfunction, shift control is performed through the output speed sensor SP2 signal. During an input speed sensor malfunction, up-shift to 5th and 6th, AI-SHIFT* and flex lock-up clutch control are prohibited. |
|
DTC P0722: Output Speed Sensor SP2 |
During an output speed sensor malfunction, shift control is performed through the input speed sensor NT signal. During an output speed sensor malfunction, up-shift to 5th and 6th, AI-SHIFT* and flex lock-up clutch control are prohibited. |
|
DTC P0710, P0712, P0713: ATF Temperature Sensor |
During an ATF temperature sensor malfunction, up-shift to 5th and 6th and flex lock-up clutch control are prohibited. |
|
Shift Solenoid Valve S1, S2, S3, S4 and SR |
The current to the malfunctioning solenoid valve is cut off and control is performed by operating the other normal solenoid valves. Shift control is effected depending on the failed solenoid as described in the table below. |
|
DTC P0748, P0778: Shift Solenoid Valve SL1 and SL2 |
During a solenoid valve SL1 or SL2 malfunction, up-shift to 5th and 6th and flex lock-up clutch control are prohibited. |
|
DTC P2714, P2716: Shift Solenoid Valve SLT |
During a solenoid valve SLT malfunction, the current to the solenoid valve is stopped. This stops line pressure optimal control, and shift shock increases. However, shifting is performed through normal clutch pressure control. |
|
DTC P2757, P2759: Shift Solenoid Valve SLU |
During a solenoid valve SLU malfunction, the current to the solenoid valve is stopped. This stops lock-up control and flex lock-up control, and fuel economy decreases. |
HINT:
*: In addition to the switching of the shift pattern through the tow/haul pattern select switch, Artificial Intelligence Shift (AI-SHIFT) control enables the ECM to estimate the road conditions and the driver's intention in order to automatically select the optimal shift pattern.
Shift Solenoid Valve Normal Operation Chart
|
Shift Lever Position |
Gear* |
Shift Solenoid S1 |
Shift Solenoid S2 |
Shift Solenoid S3 |
Shift Solenoid S4 |
Shift Solenoid SR |
Shift Solenoid SL1 |
Shift Solenoid SL2 |
|---|---|---|---|---|---|---|---|---|
|
D, S6 |
1st |
OFF |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
OFF |
ON |
OFF |
ON |
|
|
5th |
ON |
OFF |
OFF |
ON |
OFF |
ON |
OFF |
|
|
6th |
ON |
ON |
OFF |
ON |
OFF |
ON |
OFF |
|
|
S5 |
1st |
OFF |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
OFF |
ON |
OFF |
ON |
|
|
5th |
ON |
OFF |
OFF |
ON |
OFF |
ON |
OFF |
|
|
S4 |
1st |
OFF |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
OFF |
ON |
OFF |
ON |
|
|
S3 |
1st |
OFF |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd (E/B) |
ON |
OFF |
ON |
OFF |
ON |
OFF |
OFF |
|
|
S2 |
1st |
OFF |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
2nd (E/B) |
ON |
ON |
ON |
ON |
ON |
OFF |
OFF |
|
|
S1 |
1st (E/B) |
OFF |
ON |
ON |
OFF |
ON |
OFF |
OFF |
(a) Fail-safe operation for electronically malfunctioning shift solenoid valve (S1, S2, S3, S4 and SR).
(1) Fail-safe function
If any of the shift solenoid valve circuits has an open or short failure, the ECM turns the other shift solenoids "ON" and "OFF" in order to shift into the gear positions shown in the table below. Also, the ECM stops sending current to the open or short circuited solenoid.
Even if starting the engine again in the fail-safe mode, the gear position remains in the same position.
HINT:
- *: Actual gear shift (gear position) under fail-safe operation.
- X: OFF (the ECM stops sending current to the malfunctioning solenoid valve).
- Electrical malfunction: Condition is shown to the left of the "→".
- Fail-safe mode: Condition is shown to the right of the "→".
- E/B: Engine brake
Shift Solenoid Valve S1 Electrical Malfunction (P0973, P0974)
|
Shift Lever Position |
Gear* |
Shift Solenoid S1 |
Shift Solenoid S2 |
Shift Solenoid S3 |
Shift Solenoid S4 |
Shift Solenoid SR |
Shift Solenoid SL1 |
Shift Solenoid SL2 |
|---|---|---|---|---|---|---|---|---|
|
D, S6 |
1st |
X |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
1st → 4th |
X |
ON → OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
3rd → 4th |
X |
OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
4th |
X |
OFF |
OFF |
OFF |
ON |
OFF |
ON |
|
|
5th |
X |
OFF |
OFF |
ON |
OFF |
ON |
OFF |
|
|
N → 5th |
X |
ON → OFF |
OFF |
ON |
OFF |
ON |
OFF |
|
|
S5 |
1st |
X |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
1st → 4th |
X |
ON → OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
3rd → 4th |
X |
OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
4th |
X |
OFF |
OFF |
OFF |
ON |
OFF |
ON |
|
|
5th |
X |
OFF |
OFF |
ON |
OFF |
ON |
OFF |
|
|
S4 |
1st |
X |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
1st → 4th |
X |
ON → OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
3rd → 4th |
X |
OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
4th |
X |
OFF |
OFF |
OFF |
ON |
OFF |
ON |
|
|
S3 |
1st |
X |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
1st → 4th |
X |
ON → OFF |
ON → OFF |
OFF |
ON |
OFF |
ON |
|
|
3rd (E/B) → 4th |
X |
OFF |
ON → OFF |
OFF |
ON |
OFF |
OFF → ON |
|
|
S2 |
1st |
X |
ON |
ON |
OFF |
ON |
OFF |
ON |
|
2nd (E/B) → 4th |
X |
ON → OFF |
ON → OFF |
ON → OFF |
ON |
OFF |
OFF → ON |
|
|
S1 |
1st (E/B) |
X |
ON |
ON |
OFF |
ON |
OFF |
OFF |
Shift Solenoid Valve S2 Electrical Malfunction (P0976, P0977)
|
Shift Lever Position |
Gear* |
Shift Solenoid S1 |
Shift Solenoid S2 |
Shift Solenoid S3 |
Shift Solenoid S4 |
Shift Solenoid SR |
Shift Solenoid SL1 |
Shift Solenoid SL2 |
|---|---|---|---|---|---|---|---|---|
|
D, S6 |
3rd |
OFF → ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
3rd |
ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd |
ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
X |
OFF |
OFF |
ON |
OFF |
ON |
|
|
5th |
ON |
X |
OFF |
ON |
OFF |
ON |
OFF |
|
|
5th |
ON |
X |
OFF |
ON |
OFF |
ON |
OFF |
|
|
S5 |
3rd |
OFF → ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
3rd |
ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd |
ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
X |
OFF |
OFF |
ON |
OFF |
ON |
|
|
5th |
ON |
X |
OFF |
ON |
OFF |
ON |
OFF |
|
|
S4 |
3rd |
OFF → ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
3rd |
ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
|
3rd |
ON |
X |
ON |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
X |
OFF |
OFF |
ON |
OFF |
ON |
|
|
S3 |
3rd → 3rd (E/B) |
OFF → ON |
X |
ON |
OFF |
ON |
OFF |
ON → OFF |
|
3rd → 3rd (E/B) |
ON |
X |
ON |
OFF |
ON |
OFF |
ON → OFF |
|
|
3rd (E/B) |
ON |
X |
ON |
OFF |
ON |
OFF |
OFF |
|
|
S2 |
3rd → 3rd (E/B) |
OFF → ON |
X |
ON |
OFF |
ON |
ON → OFF |
ON → OFF |
|
3rd (E/B) |
ON |
X |
ON |
ON → OFF |
ON |
OFF |
OFF |
|
|
S1 |
3rd (E/B) |
OFF → ON |
X |
ON |
OFF |
ON |
OFF |
OFF |
Shift Solenoid Valve S3 Electrical Malfunction (P0979, P0980)
|
Shift Lever Position |
Gear* |
Shift Solenoid S1 |
Shift Solenoid S2 |
Shift Solenoid S3 |
Shift Solenoid S4 |
Shift Solenoid SR |
Shift Solenoid SL1 |
Shift Solenoid SL2 |
|---|---|---|---|---|---|---|---|---|
|
D, S6 |
3rd → 4th |
OFF |
ON |
X |
OFF |
ON |
OFF |
ON |
|
4th |
ON |
ON → OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
5th |
ON |
OFF |
X |
ON |
OFF |
ON |
OFF |
|
|
6th |
ON |
ON |
X |
ON |
OFF |
ON |
OFF |
|
|
S5 |
3rd |
OFF |
ON |
X |
OFF |
ON |
OFF |
ON |
|
4th |
ON |
ON → OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
5th |
ON |
OFF |
X |
ON |
OFF |
ON |
OFF |
|
|
S4 |
3rd |
OFF |
ON |
X |
OFF |
ON |
OFF |
ON |
|
4th |
ON |
ON → OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
S3 |
3rd |
OFF |
ON |
X |
OFF |
ON |
OFF |
ON |
|
4th |
ON |
ON → OFF |
X |
OFF |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
X |
OFF |
ON |
OFF |
OFF → ON |
|
|
S2 |
3rd |
OFF |
ON |
X |
OFF |
ON |
OFF |
ON |
|
6th → 4th |
ON |
ON → OFF |
X |
ON → OFF |
ON |
OFF |
OFF → ON |
|
|
S1 |
1st |
OFF |
ON |
X |
OFF |
ON |
OFF |
OFF |
Shift Solenoid Valve S4 Electrical Malfunction (P0982, P0983)
|
Shift Lever Position |
Gear* |
Shift Solenoid S1 |
Shift Solenoid S2 |
Shift Solenoid S3 |
Shift Solenoid S4 |
Shift Solenoid SR |
Shift Solenoid SL1 |
Shift Solenoid SL2 |
|---|---|---|---|---|---|---|---|---|
|
D, S6 |
1st |
OFF |
ON |
ON |
X |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
X |
ON |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
X |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
X |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
X |
OFF → ON |
ON → OFF |
OFF → ON |
|
|
4th |
ON |
ON → OFF |
OFF |
X |
OFF → ON |
ON → OFF |
OFF → ON |
|
|
S5 |
1st |
OFF |
ON |
ON |
X |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
X |
ON |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
X |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
X |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
X |
OFF → ON |
ON → OFF |
OFF → ON |
|
|
S4 |
1st |
OFF |
ON |
ON |
X |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
X |
ON |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
X |
ON |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
X |
ON |
OFF |
ON |
|
|
S3 |
1st |
OFF |
ON |
ON |
X |
ON |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
X |
ON |
OFF |
ON |
|
|
3rd (E/B) |
ON |
OFF |
ON |
X |
ON |
OFF |
OFF |
|
|
S2 |
1st |
OFF |
ON |
ON |
X |
ON |
OFF |
ON |
|
2nd (E/B) |
ON |
ON |
ON |
X |
ON |
OFF |
OFF |
|
|
S1 |
1st (E/B) |
OFF |
ON |
ON |
X |
ON |
OFF |
OFF |
Shift Solenoid Valve SR Electrical Malfunction (P0985, P0986)
|
Shift Lever Position |
Gear* |
Shift Solenoid S1 |
Shift Solenoid S2 |
Shift Solenoid S3 |
Shift Solenoid S4 |
Shift Solenoid SR |
Shift Solenoid SL1 |
Shift Solenoid SL2 |
|---|---|---|---|---|---|---|---|---|
|
D, S6 |
1st |
OFF |
ON |
ON |
OFF |
X |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
X |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
OFF |
X |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
OFF |
X |
OFF |
ON |
|
|
5th |
ON |
OFF |
OFF |
ON |
X |
ON |
OFF |
|
|
6th |
ON |
ON |
OFF |
ON |
X |
ON |
OFF |
|
|
S5 |
1st |
OFF |
ON |
ON |
OFF |
X |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
X |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
OFF |
X |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
OFF |
X |
OFF |
ON |
|
|
5th |
ON |
OFF |
OFF |
ON |
X |
ON |
OFF |
|
|
S4 |
1st |
OFF |
ON |
ON |
OFF |
X |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
X |
OFF |
ON |
|
|
3rd |
ON |
OFF |
ON |
OFF |
X |
OFF |
ON |
|
|
4th |
ON |
OFF |
OFF |
OFF |
X |
OFF |
ON |
|
|
S3 |
1st |
OFF |
ON |
ON |
OFF |
X |
OFF |
ON |
|
2nd |
ON |
ON |
ON |
OFF |
X |
OFF |
ON |
|
|
3rd (E/B) |
ON |
OFF |
ON |
OFF |
X |
OFF |
OFF |
|
|
S2 |
1st |
OFF |
ON |
ON |
OFF |
X |
OFF |
ON |
|
2nd (E/B) |
ON |
ON |
ON |
ON |
X |
OFF |
OFF |
|
|
S1 |
1st (E/B) |
OFF |
ON |
ON |
OFF |
X |
OFF |
OFF |
(b) Fail-safe operation in the event of a mechanical system malfunction.
(1) Fail-safe function
The ECM controls the gear position as shown in the table below when malfunctions occur.
|
DTC |
Condition |
Gear*1 |
|||||
|---|---|---|---|---|---|---|---|
|
- |
Normal |
1st |
2nd |
3rd |
4th |
5th |
6th |
|
P0751 |
Shift solenoid valve S1: Stuck OFF malfunction |
1st*2 |
1st*2 |
3rd |
3rd |
3rd |
3rd |
|
P0761 |
Shift solenoid valve S3: Stuck ON malfunction |
1st |
2nd |
3rd |
3rd |
3rd |
3rd |
|
P0766 P0776 |
Shift solenoid valve S4, Shift solenoid valve SL2 or Valve body (brake control valve): Malfunction |
1st |
2nd |
3rd |
3rd |
3rd |
3rd |
|
P0781 |
Valve body (1-2 shift valve): Malfunction |
1st*2 |
1st*2 |
3rd |
3rd |
3rd |
3rd |
|
P0729 |
Valve body (sequence valve): Malfunction |
1st |
2nd |
3rd |
3rd |
3rd |
3rd |
HINT:
- *1: Actual gear shift (gear position) under fail-safe operation.
- *2: Under engine braking, downshifting to 1st or 2nd gear is prohibited.
|
|