Test Cases for Transmission Pressure, Fuel Level, and Torque Converter Temp

Sensor Signal Conversion

The three controllers—transmission oil pressure, fuel level, and torque converter temperature—receive analog voltage inputs that are converted to digital signals using the following formulas (with V as the measured voltage and c as a calibration constant):

Transmission oil pressure : 1.25V<sub>c</sub> - 0.75 Range: 0 ~ 4.0 MPa Allowed error: ±0.1 MPa

Fuel level : V<sub>c</sub> * 3 - 5 Range: 0 % ~ 100 % Allowed error: ±1 %

Torque converter temperature : V<sub>c</sub> * 500/3 - 25 Range: 0 °C ~ 150 °C Allowed error: ±1.5 °C

Derived Voltage Test Ranges

By solving the formulas for the voltage V, the following voltage intervals are obtained, and test cases are created around the boundaries:

Transmission pressure : V ≈ 0.6 V – 3.8 V → test cases < 0.6 V, ≈0.6 V, between 0.6 V‑3.8 V, ≈3.8 V, > 3.8 V.

Fuel level : V ≈ 0.15 V – 1.05 V → test cases < 0.15 V, ≈0.15 V, between 0.15 V‑1.05 V, ≈1.05 V, > 1.05 V.

Torque converter temperature : V ≈ 0.1 V – 1.5 V → test cases < 0.1 V, ≈0.1 V, between 0.1 V‑1.5 V, ≈1.5 V, > 1.5 V.

Automotive Lighting Control Logic

The vehicle head‑lamp system includes a roof light, left/right turn signals, illumination light, width‑indicator, high‑beam, low‑beam, brake light, anti‑air brake light, and anti‑air illumination light. The following switches affect the lights:

IGN (main power)

Anti‑air switch

Alarm switch

Left‑turn switch

Right‑turn switch

Width‑indicator switch

Low‑beam switch

High‑beam switch

Brake switch

Key logical rules (summarized):

If IGN is OFF, all lights except the alarm are ineffective.

If IGN is ON and anti‑air is ON, the roof light, high‑beam, low‑beam, turn signals, width‑indicator, and brake light are forced OFF; the alarm switch becomes ineffective.

When anti‑air is ON, the anti‑air brake light follows the brake switch and stays OFF.

If anti‑air is OFF and the alarm is ON, left and right turn signals flash synchronously, overriding their individual switches.

Low‑beam must be ON for the high‑beam to be controllable.

When anti‑air is OFF, the roof light is ON and the illumination light follows the width‑indicator switch.

Test Case Design Strategy

Test cases are grouped by functional mode:

Group A – IGN OFF : Verify that all lights are off (alarm may be considered ineffective).

Group B – Anti‑air mode (IGN ON, anti‑air ON) : Expect roof light OFF, all other lights forced OFF, alarm ineffective, and anti‑air brake light controlled by the brake switch.

Group C – Normal mode (IGN ON, anti‑air OFF) : Further divided into sub‑scenarios:

C1 – Alarm priority: alarm ON forces both turn signals to flash.

C2 – Low‑beam prerequisite: high‑beam only lights when low‑beam is ON.

C3 – Independent turn‑signal control when alarm is OFF.

C4 – Width‑indicator controls illumination light.

C5 – Brake‑light logic, including anti‑air brake light binding.

Each sub‑scenario lists explicit input combinations (IGN, anti‑air, alarm, left/right turn, width, low‑beam, high‑beam, brake) and the expected lamp states (ON/OFF or forced OFF). The original document provides a detailed matrix of these combinations.

Suggested Supplementary Tests

State‑transition tests : e.g., in normal mode, turn the left‑turn light ON, then enable the alarm and verify immediate switch to double‑flash, then disable the alarm and verify return to left‑turn.

Conflict tests : In anti‑air mode, toggle other switches and confirm no lamp response.

Boundary/exception tests : Rapidly toggle switches at high frequency to check for stable lamp behavior without flicker or lock‑up.

Interlock tests : Verify that the alarm and anti‑air switches are mutually exclusive as intended.

Power‑consumption / safety tests : Measure current and temperature when all lamps are illuminated simultaneously (if the design permits).

The presented test‑case table covers every logical branch described in the requirements and can serve as a baseline for functional verification. Real‑world testing may need adjustments based on hardware specifics such as driver circuits and switch types.