Road Test
- This test determines if the problem is related to a mechanical or electrical component.
- Stop engine and disconnect Transmission Control Unit (TCU) or TCU fuse.
- Road test vehicle. Shift transmission into each gear range. Transmission should operate as follows:
- Lock in Park.
- Back up in Reverse.
- Not move in Neutral.
- Provide first gear only with shift lever in 1-2 position.
- Operate in third gear only with shift lever in 3 position.
- Operate in overdrive fourth gear in "D" position.
- If transmission operates as described, proceed to next step. However, if forward gear ranges were difficult to distinguish (all feel the same) or vehicle would not back up, refer to diagnosis charts. DO NOT perform stall or time lag tests.
- Continue road test. Manually downshift transmission from D to 3, and from 3 to 1-2 position. Manually upshift transmission through forward ranges again.
- If transmission operation is okay, perform stall, time lag and pressure tests. If problem is encountered, see TROUBLE SHOOTING .
- If a problem still exists, check electronic control system. See AISIN WARNER 4 ELECTRONIC CONTROLS article.
CAUTION:
DO NOT over rev the engine during the next test step. Ease off the throttle and allow the vehicle to slow before downshifting.