Open vs Closed Loop

[anitelite]

We just mounted an active scan tool on my 05 LE I4 and noticed an odd thing. Whenever I take my foot off the gas and cover the brake pedal, the computer drops out of closed loop and goes open. Once the car slows, it goes back into closed loop. It does this every time I pull my foot off the gas or reduce the pressure to idle. Is this just a part of the drive by wire hesitation? My friend has a Scion which has an actual throttle cable and his never jumps out of closed loop unless he floors it on acceleration. Does this indicate a sensor or throttle position problem?

Jim

[white90dx]

Try again.

When your foot is off the gas and the motor is not close to idle (>1500rpm or so?), the ECU is not injecting any fuel. No fuel = no combustion = no A/F ratio to monitor = open loop.

Your friend's Scion is just reporting to the scan tool slightly differently.

-Charlie