AUTOMATIC TRANSMISSION SYSTEM > FAIL-SAFE CHART |
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FAIL-SAFE CHART |
Fail-safe function:
If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid ON and OFF to shift to the gear positions shown in the table below. The ECM also turns the shift solenoid valve SL OFF at the same time. If both solenoids are malfunctioning, electronic hydraulic control does not operate and must be performed manually. Manual shifting as shown in the following table must be performed.
In case of a short circuit, the ECM stops sending current to the circuit.
Malfunction Part | Function |
DTC P0710/38, P0712/38 and P0713/38: ATF Temperature Sensor | During malfunction of ATF temperature sensor, system fixes ATF at 80°C (176°F) |
DTC P0722/61: Speed Sensor (SP2) | During speed sensor (SP2) malfunction, shift lever control is effected through input speed sensor signal (NC0) or engine speed signal (NE) |
DTC P0973/62, P0974/62, P0976/63 and P0977/63: Shift Solenoid Valve S1, S2 | Current to the malfunctioning solenoid valve is cut off and control is performed by operating other normal solenoid valves |
DTC P2716/77: Shift Solenoid Valve SLT | During solenoid valve SLT malfunction, current to solenoid valve is stopped. Because this stops line pressure control, shift shock increases. However, shifting is effected through normal clutch pressure control. |
DTC P2769/64 and P2770/64: Shift Solenoid Valve SL | During solenoid valve SL malfunction, current to solenoid valve is stopped. Because this stops lock-up control, fuel economy decreases. |
Position | Normal | Shift Solenoid S1 Malfunctioning | Shift Solenoid S2 Malfunctioning | Both Solenoids Malfunctioning | ||||||
Solenoid valve | Gear | Solenoid valve | Gear | Solenoid valve | Gear | Gear when shift selector is manually operated | ||||
S1 | S2 | S1 | S2 | S1 | S2 | |||||
D | ON | OFF | 1st | X | ON | 3rd | ON | X | 1st | 4th |
ON | ON | 2nd | X | ON | 3rd | OFF | X | 4th | 4th | |
OFF | ON | 3rd | X | ON | 3rd | OFF | X | 4th | 4th | |
OFF | OFF | 4th | X | OFF | 4th | OFF | X | 4th | 4th | |
2 | ON | OFF | 1st | X | ON | 3rd | ON | X | 1st | 3rd |
ON | ON | 2nd | X | ON | 3rd | OFF | X | 3rd | 3rd | |
OFF | ON | 3rd | X | ON | 3rd | OFF | X | 3rd | 3rd | |
L | ON | OFF | 1st | X | OFF | 1st | ON | X | 1st | 1st |
ON | ON | 2nd | X | ON | 2nd | ON | X | 1st | 1st |
- HINT:
- X: Malfunction