AT1–72 AT340E (2JZ–GE) AUTOMATIC TRANSMISSION – TROUBLESHOOTING DTC 62 63 No.1 No. 2 Solenoid Valve Circuit CIRCUIT DESCRIPTION Shifting from 1st to O/D is done in combination with ON and OFF of the No.1 and No.2 solenoid valves controlled by ECM. If an open or short circuit occurs in either of the solenoid valves, the ECM controls the remaining normal solenoid to allow the vehicle to be operated smoothly (Fail safe function). Fail Safe Function If either of the solenoid valve circuits develops a short or an open, the ECM turns the other solenoid ON and OFF to shift to the gear positions shown in the table below. The ECM also turns the lock–up solenoid valve OFF at the same time. If both solenoids malfunction, hydraulic control cannot be performed electronically and must be done manually. Manual shifting as shown in the following table must be done (In the case of a short circuit, the ECM stops sending current to the short circuited solenoid). Position | NORMAL | NO.1 SOLENOID MALFUNCTIONING | NO.2 SOLENOID MALFUNCTIONING | BOTH SOLENOIDS MALFUNCTIONING Solenoid valve | Gear | Solenoid valve | Gear | Solenoid valve | Gear | Gear when shift selector is manually operated No.1 | No.2 | | No.1 | No.2 | | No.1 | No.2 | | D ON | OFF | 1st | X | ON | 3rd | ON | X | 1st | O/D ON | ON | 2nd | X | ON | 3rd | OFF | X | O/D | O/D OFF | ON | 3rd | X | ON | 3rd | OFF | X | O/D | O/D OFF | OFF | O/D | X | OFF | O/D | OFF | X | O/D | O/D 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 X: Malfunctions Check the No.1 solenoid when diagnostic trouble code 62 is output and check and No.2 solenoid when diagnostic trouble code 63 is output. DTC No. | Diagnostic Trouble Code Detection Condition | Trouble Area 62, 63 (a) Solenoid resistance is 8 Ω or lower (short circuit) when solenoid is energized. (b) Solenoid resistance is 100 kΩ or higher (open circuit) when solenoid is not energized. The ECM checks for an open or short circuit in the No.1 and No.2 solenoid circuit when it changes gear position. The ECM records diag. trouble code 62 or 63 if condition (a) or (b) is detected once, but it does not blink the O/D OFF indicator light. After the ECM detects the condition (a) or (b) continuously 8 times or more in one–trip *, it causes the O/D OFF indicator light to blink until condition (a) or (b) disappears. After that, if the ECM detects condition (a) or (b) one, it starts blinking the O/D OFF indicator light again. • Solenoid valve • Harness or connector between solenoid and • ECM • ECM * one–trip (1st trip) See page AT1–54