Toyota Avalon (XX50): Fail-safe Chart

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Drivetrain / Ua80e Automatic Transmission / Transaxle / Automatic Transaxle System / Fail-safe Chart

FAIL-SAFE CHART

Description

The fail-safe function minimizes the loss of operation when a malfunction occurs in a sensor or solenoid.

Fail-safe

(a) Fail-safe control list:

Malfunctioning Part	Function
Transmission Revolution Sensor (NT)	Lock up clutch control is prohibited. High response gear shifts are prohibited.
Transmission Revolution Sensor (NC)	Lock up clutch control is prohibited. High response gear shifts are prohibited.
Solenoid (SL1, SL2, SL3, SL4, SL5, SL6, SLT, SLU and SL) valve	If the ECM detects a solenoid valve malfunction, it performs fail-safe control.
ATF temperature sensor	Lock up clutch control is prohibited. High response gear shifts are prohibited.
ECM power supply (voltage is low)	When driving in 1st to 5th gear when a malfunction is detected, the transaxle will be fixed in 5th gear. When driving in 6th to 8th gear when a malfunction is detected, the transaxle will be fixed in the current gear.
Knock sensor	When driving in 1st to 5th gear when a malfunction is detected, up-shift to 6th or higher will be prohibited. When driving in 6th gear or higher when a malfunction is detected, up-shift to a higher gear will be prohibited. Lock up clutch control is prohibited. High response gear shifts are prohibited.
CAN communication	When driving in 1st to 3rd gear when a malfunction is detected, the transaxle will be fixed in 3rd gear. When driving in 4th to 8th gear when a malfunction is detected, up-shift to a higher gear will be prohibited. Lock up clutch control is prohibited. High response gear shifts are prohibited.
Solenoid (SLU) valve	Lock up clutch control is prohibited. Shifting to or from 3rd or 4th gear is prohibited. Shifting to or from 6th, 7th or 8th gear is prohibited.
Solenoid (SLT) valve	Engine output is limited. High response gear shifts are prohibited. Lock up clutch control is prohibited. The transaxle will be fixed in 5th gear.

(b) Solenoid Valve Normal Operation Chart:

Gear	1st	2nd	3rd	4th	5th	6th	7th	8th
Solenoid (SL1) Valve	ON	ON	ON	ON	ON	OFF	OFF	OFF
Solenoid (SL2) Valve	OFF	OFF	OFF	OFF	ON	ON	ON	ON
Solenoid (SL3) Valve	OFF	OFF	ON	OFF	OFF	OFF	ON	OFF
Solenoid (SL4) Valve	OFF	OFF	OFF	ON	OFF	ON	OFF	OFF
Solenoid (SL5) Valve	OFF	ON	OFF	OFF	OFF	OFF	OFF	ON
Solenoid (SL6) Valve	ON	OFF	OFF	OFF	OFF	OFF	OFF	OFF

*1: Operation of fail-safe is canceled the first time the vehicle is stopped.

*2: Operation of fail-safe is not canceled for subsequent times the vehicle is stopped.

Fail-safe operation is performed when the ECM detects a malfunction.

Fail-safe Control Chart (Solenoid (SL1) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	1st	2nd	3rd	4th	5th	4th to 5th	3rd to 5th	5th
Fail-safe control during ON malfunction	1st	2nd	3rd	4th	5th	5th	5th	5th
OFF malfunction (without fail-safe control)	N*	N*	N*	N*	N*	6th	7th	8th
Fail-safe control during OFF malfunction	6th	6th	6th	6th	6th	6th	7th	8th

Fail-safe Control Chart (Solenoid (SL2) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	5th	5th	3rd to 5th	4th to 5th	5th	6th	7th	8th
Fail-safe control during ON malfunction	5th	5th	5th	5th	5th	6th	7th	8th
OFF malfunction (without fail-safe control)	1st	2nd	3rd	4th	N*	N*	N*	N*
Fail-safe control during OFF malfunction	1st	2nd	3rd	4th	4th	4th	4th	4th

Fail-safe Control Chart (Solenoid (SL3) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	3rd	3rd	3rd	3rd	3rd to 5th	7th	7th	7th
Fail-safe control during ON malfunction	3rd	3rd	3rd	3rd	3rd	7th	7th	7th
OFF malfunction (without fail-safe control)	1st	2nd	N*	4th	5th	6th	N*	8th
Fail-safe control during OFF malfunction	1st	2nd	4th	4th	5th	6th	6th	8th

Fail-safe Control Chart (Solenoid (SL4) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	4th	4th	3rd	4th	4th to 5th	6th	7th	6th
Fail-safe control during ON malfunction	4th	4th	4th	4th	4th	6th	6th	6th
OFF malfunction (without fail-safe control)	1st	2nd	3rd	N*	5th	N*	7th	8th
Fail-safe control during OFF malfunction	1st	2nd	3rd	5th	5th	7th	7th	8th

Fail-safe Control Chart (Solenoid (SL5) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	N*	2nd	3rd	4th	5th	6th	7th	8th
Fail-safe control during ON malfunction	2nd	2nd	3rd	4th	5th	6th	7th	8th
OFF malfunction (without fail-safe control)	1st	N*	3rd	4th	5th	6th	7th	N*
Fail-safe control during OFF malfunction	3rd	3rd	3rd	4th	5th	6th	7th	7th

Fail-safe Control Chart (Solenoid (SL6) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	1st	N*	3rd	4th	5th	6th	7th	N*
Fail-safe control during ON malfunction	3rd	3rd	3rd	4th	5th	6th	7th	7th
OFF malfunction (without fail-safe control)	N*	2nd	3rd	4th	5th	6th	7th	8th
Fail-safe control during OFF malfunction	2nd	2nd	3rd	4th	5th	6th	7th	8th

Fail-safe Control Chart (Solenoid (SLT) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
OFF malfunction (without fail-safe control) (MAX Pressure)	1st	5th	3rd to 5th	4th to 5th	5th	4th to 5th	3rd to 5th	5th
Fail-safe control during ON malfunction	Fixed in 5th

Gear Under Normal Conditions

1st

2nd

3rd

4th

5th

6th

7th

8th

OFF malfunction

(without fail-safe control)

(MAX Pressure)

1st

5th

3rd to 5th

4th to 5th

5th

4th to 5th

3rd to 5th

5th

Fail-safe control during ON malfunction

Fixed in 5th

Fail-safe Control Chart (Solenoid (SLU) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control)	1st	2nd	3rd or N*	4th or N*	5th	6th or N*	7th or N*	8th
Fail-safe control during ON malfunction	1st	2nd	5th	5th	5th	5th	5th	8th

Gear Under Normal Conditions

1st

2nd

3rd

4th

5th

6th

7th

8th

*: Neutral

ON malfunction

(without fail-safe control)

1st

2nd

3rd or N*

4th or N*

5th

6th or N*

7th or N*

8th

Fail-safe control during ON malfunction

1st

2nd

5th

8th

Fail-safe Control Chart (Solenoid (SL) Valve)

Gear Under Normal Conditions	1st	2nd	3rd	4th	5th	6th	7th	8th
*: Neutral
ON malfunction (without fail-safe control) (MIN Pressure)	1st	2nd	3rd or N*	4th or N*	5th	6th or N*	7th or N*	8th
Fail-safe control during ON malfunction	1st	2nd	5th	5th	5th	5th	5th	8th

Gear Under Normal Conditions

1st

2nd

3rd

4th

5th

6th

7th

8th

*: Neutral

ON malfunction

(without fail-safe control)

(MIN Pressure)

1st

2nd

3rd or N*

4th or N*

5th

6th or N*

7th or N*

8th

Fail-safe control during ON malfunction

1st

2nd

5th

8th

HINT:

In the case of an open or short, the ECM stops sending current to the open or shorted solenoid.

Diagnosis System. Diagnostic Trouble Code Chart. Dtc Check / Clear

How To Proceed With Troubleshooting. Hydraulic Test. Initialization

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