![]() ![]() It returns when misfiring isn't detected. If I'm not mistaken, cruise control is defeated temporarily when misfiring occurs. Most describe this as limp home mode as the engine computer defaults to around 15% power to allow driving off the highway or local street to make the emergency call for help without killing the engine. Dual position sensors in throttle and pedal feedback signals to prevent engine runaway with a default known as reduced throttle mode - the engine symbol with a large down arrow indicator when one of four sensors fail. The electronic pedal tells the ecm to move throttle. Throttle is electric with a small dc servo motor driven from the ecm. As you may or may not know, our throttles are no longer physically connected to the pedal. The return spring is to have a backup in case power is lost to ensure throttle closes, precluding any chance of a runaway engine. I use a wooden handle from a cleaning brush to prop open throttle for cleaning. There's a hidden (strong) return spring inside the throttle assembly. If you can, remove or clean the throttle in place. 12v sits on both sides of injector connections until the ecm commands a ground signal to energize each injector. This makes both connections hot with ignition on, measured to engine ground. Each injector is electronically switched to ground to operate them from the ecm. All injectors are wired in parallel insofar as 12v power. If you insist, measure adjacent injectors since you know five are working. You can always swap injectors around to see if the problem follows the suspect injector instead of measuring injector resistance. The flashing check engine light is the only indication of possible damage to catcons if the problem isn't fixed. Catcons can burn out prematurely if allowed to run with one cylinder not igniting the air/fuel mixture as the unburned fuel raises catcon temperatures above its normal operating specs and will burn out in 50 miles or so. That cylinder had fuel to verify injector operation. With one coil dead, the engine was very lumpy and not good for the catcon. I didn't bother to check injectors with around 105k miles as the engine was always smooth idling before and after coil pack replacement. It would have been nice to see what compression numbers were for all three cylinders to verify a coil failure. Replacing the coil pack solved the misfiring and error code. The borrowed compression gauge from a local AutoZone was faulty and a spark test didn't seem conclusive when seeing spark. My misfire occurred out of nowhere and presuming compression was fine, I ordered a coil pack for the front bank. It's always recommended that you take your vehicle to a professional mechanic to diagnose and fix the problem, as these are complex systems and require specialized knowledge and equipment to fix.With the same 3.0L V6 engine used in 元00s, some things could have been checked when replacing the coil pack - compression in the cylinders to compare one against the other two, examining spark plugs for wear if any. Once the codes are retrieved, it would give a better idea of what component is causing the misfire. It's recommended to have the vehicle scanned with a diagnostic scanner to retrieve the trouble codes and determine the source of the problem. ![]() The ECM should be checked and reprogrammed if necessary.
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