System Description
WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
Based on signals from the transmission speed sensors (NT, SP2 and NC3), the actual gear is detected If the detected gear is different than the commanded gear, the TCM detects related mechanical problems in the shift solenoid valves, valve body and automatic transmission
HINT
Actual gear when a problem occurs in shift solenoid valve SL3
SHIFT SOLENOID VALVE REFERENCE
| TCM commanded gear |
1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
8th |
| Actual gear during SL3 stuck ON malfunction |
3rd |
3rd |
3rd |
3rd |
7th |
7th |
7th |
7th |
| Actual gear during SL3 stuck OFF malfunction |
1st |
2nd |
N (1st) |
4th |
5th |
6th |
N |
8th |
DTC DETECTION CONDITION AND TROUBLE AREA
| DTC Code |
DTC Detection Condition
- Diagnosis Condition
- Malfunction Status
- Malfunction Time
- Other
|
Trouble Area |
| P0796 |
- ECT is 40°C (104°F) or more, ATF temperature is -10°C (14°F) or more, and vehicle is driven with shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, speed sensors (NT, NC3, SP2), water temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)
- One of following occurs
- When gear shifts to 1st are requested by TCM, actual gear changes to 3rd gear
- When gear shifts to 2nd are requested by TCM, actual gear changes to 3rd gear
- When gear shifts to 4th are requested by TCM, actual gear changes to 3rd gear
- When gear shifts to 5th are requested by TCM, actual gear changes to 7th gear
- When gear shifts to 6th are requested by TCM, actual gear changes to 7th gear
- When gear shifts to 8th are requested by TCM, actual gear changes to 7th gear
- Malfunction status occurs 2 times per trip
- 2 trip detection logic
|
- Shift solenoid valve SL3
- Shift solenoid valve SL4
- Shift solenoid valve SR
- Shift solenoid valve SLT
- Valve body assembly
- Automatic transmission assembly
|
| P0796 |
- ECT is 40°C (104°F) or more, ATF temperature is -10°C (14°F) or more, and vehicle is driven with shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, speed sensors (NT, NC3, SP2), water temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)
- When gear shifts to 3rd or 7th are requested by TCM, engine speed overruns (neutral status)
- Malfunction status continues for 0 5 sec or more (1 trip)
- 2 trip detection logic
|
- Shift solenoid valve SL3
- Shift solenoid valve SLT
- Valve body assembly
- Automatic transmission assembly
|