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Last Modified: 9-16-2014 6.6 C Doc ID: RM000000W8I073X Model Year: 2015 Model: Tundra Prod Date Range: [08/2014 - ] Title: A760E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0729; Gear 6 Incorrect Ratio; 2015 MY Tundra [08/2014 - ] DTC P0729 Gear 6 Incorrect Ratio DESCRIPTION The ECM uses signals from the output speed sensor SP2 and input speed sensor NT to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th gear). Then the ECM compares the actual gear with the shift schedule in DTC CODE DTC DETECTION CONDITION TROUBLE AREA P0729 6th gear shift malfunction: The ECM determines there is a malfunction when both (a) When the ECM directs the transmission to switch to 5th gear, the actual gear is shifted to 5th. (b) When the ECM directs the transmission to switch to 6th gear, the actual gear is shifted to 4th. Valve body is blocked or stuck (sequence valve) Shift solenoid valve SLT remains open or closed Automatic transmission (clutch, brake, gear, etc.) HINT: 1st 2nd 3rd 4th 5th 6th Actual gear position under malfunction 1st 2nd 3rd 4th 5th 4th Gear position during fail-safe operation: If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below. Gear position under normal conditions 1st 2nd 3rd 4th 5th 6th Actual gear position under fail-safe mode 1st 2nd 3rd 3rd 3rd 3rd MONITOR DESCRIPTION The ECM commands gear shifts by turning the shift solenoid valves ON/OFF and switching oil pressure to the valves in the valve body. This DTC indicates that the sequence valve is locked in the direction the spring stretches and that shifting to 6th gear is impossible. MONITOR STRATEGY A760E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMIS... |