Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Lexus IS FFACTORY OEM SERVICE PROCEDURE
Definition Of Terms
DEFINITION OF TERMS
| Term | Definition |
|---|---|
| Monitor description | Description of what the TCM monitors and how it detects malfunctions (monitoring purpose and its details) |
| Related DTCs | Group of diagnostic trouble codes that are output by the TCM based on the same malfunction detection logic |
| Typical enabling condition | Preconditions that allow the TCM to detect malfunctions With all preconditions satisfied, the TCM sets the DTC when the monitored value (s) exceeds the malfunction threshold (s) |
| Sequence of operation | The priority order that is applied to monitoring if multiple sensors and components are used to detect the malfunction While another sensor is being monitored, the next sensor or component will not be monitored |
| Required sensor/Components | The sensors and components that are used by the TCM to detect malfunctions |
| Frequency of operation | The number of times that the TCM checks for malfunctions per driving cycle "Once per driving cycle" means that the TCM detects malfunction only 1 time during a single driving cycle "Continuous" means that the TCM detects a malfunction every time the enabling condition is met |
| Duration | The minimum time that the TCM must sense a continuous deviation in the monitored value (s) before setting a DTC This timing begins after the "typical enabling conditions" are met |
| Malfunction thresholds | Beyond this value, the TCM will conclude that there is a malfunction and set a DTC |
| MIL operation | MIL illumination timing after a malfunction is detected "Immediate" means that the TCM illuminates the MIL the instant the TCM determines that there is a malfunction "2 driving cycles" means that the TCM illuminates the MIL if the same malfunction is detected again in the 2nd driving cycle |
| Component operating range | Normal operation range of sensors and solenoids under normal driving conditions Use these ranges as a reference They cannot be used to judge if a sensor or solenoid is defective or not |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.