What is the amount of time the PCM remains in open-loop when the engine is below a certain temperature?

• A. Cold Delay
• B. Short Warm-Up
• C. Open-Loop Duration
• D. Low-Temp Window

Answer: (A)

Cold delay is the period when the PCM stays in open-loop fueling because the engine is still below the temperature threshold. At cold starts, sensors like the oxygen sensor and catalytic converter aren’t up to operating temperature yet, so the PCM uses fixed fueling maps rather than feedback from the O2 sensor. This deliberate delay prevents unreliable sensor readings from throwing off fuel delivery. Once the coolant (or sensor) temperature crosses the threshold, the system switches to closed-loop and uses the oxygen sensor to trim fuel for the correct air/fuel ratio. The other terms aren’t the standard label for this cold-start behavior, making cold delay the best fit.