Diagnosis and Testing - Road Test Vehicle

Shift Point Road Test

Upshift Sequence

Occasionally the 10-speed transmission may skip gears when the vehicle starts moving from a complete stop. This is normal and desired behavior.

During hard acceleration, a single-step upshift will result in very frequent shifts (very short time in each gear). A double upshift results in increased time spent in each gear.

However, with light pedal and with heavy pedal, a single-step upshift will occur. With light pedal, the small 10-speed gear steps allow the engine speed to drop to lower values than would occur in a 6-speed transmission, providing the best fuel economy. Conversely, with heavy or maximum pedal, the small 10-speed gear steps keep the engine closer to the peak power for better performance.

Downshift Sequence

The 10-speed transmission may occasionally skip gears when the vehicle downshifts to a complete stop. This is a normal and desired operation.

The same skip shift strategy used for upshifts may be applied during downshifts.

Road Test

Most powertrain-related automatic transmission Diagnostic Trouble Codes (DTCs) require the fault to be detected several times before the DTC is set. In many cases the fault must be detected a consecutive number of times (up to five). Performing the shift point road test detailed below increases the likelihood that the DTC will be set if a fault is present in the system.

1. 1
   Bring the engine and transmission to normal operating temperature.
2. 2
   Drive the vehicle with the selector lever in the D position.
3. 3
   From a stop, accelerate the vehicle to 100 km/h, with shifts occurring at approximately 2000 rpm. Remain in 10th gear for 30 seconds or until the TCC applies. Repeat this twice.
4. 4
   From a stop, accelerate the vehicle to 100 km/h, with shifts occurring at approximately 3000 rpm. Remain in 10th gear for 30 seconds or until the TCC applies. Repeat this twice.
5. 5
   If the transmission does not shift up or down,
   REFER TO: Symptom Chart (307-01A Automatic Transmission - 10-Speed Automatic Transmission - 10R60, Diagnosis and Testing).

Shift Speed Chart