Experiencing a persistent alarm for a Knock Sensor Malfunction can be frustrating for any boat owner. Recently, a user encountered this very issue on their 2006 SN196 Ltd., marked by an alarm sounding every minute and displaying code 44, indicating a sensor malfunction rather than an actual engine knock. This article delves into their troubleshooting journey, highlighting the effective use of a Car Obdii Reader Pcm to diagnose and resolve the problem, offering valuable insights for those facing similar challenges.
Initially, the boat owner had the issue addressed by a dealer who replaced the knock sensor and cleared the code. However, the fault recurred after only 10 hours of use (5 hours by the previous owner and 5 hours after purchase). Suspecting potential underlying issues, the owner embarked on a series of diagnostic steps. This included replacing the spark plugs, which appeared dry and burnt, and addressing potentially degraded fuel. New plug wires and fuel filters were also ordered as part of a comprehensive maintenance approach.
To further isolate the problem, a clever test was devised to assess the knock sensor itself. A new knock sensor was purchased, and instead of installing it directly, it was connected to the existing wiring harness, bypassing the originally installed sensor. The new sensor’s housing was grounded to the engine block using an alligator clip wire, and it was wrapped in a towel to prevent any accidental shocks. A test run was then conducted. Contrary to the dealer’s suggestion that fixing the root cause would automatically clear the fault code alarm, the alarm persisted. This observation correctly pointed towards the necessity of manual code clearing, even after addressing the potential underlying issue.
To effectively clear the code and further investigate, the boat owner acquired a Codemate #94008 scan tool, a car OBDII reader PCM mentioned in an older forum post. This tool was sourced from Michigan Motors, a marine supply shop in the Detroit area. The engine featured a diagnostic connector located at the top front center, which was connected to a POS Gateway box. To use the scan tool, this connection had to be temporarily disconnected. The engine also had a single wire connector, matching one connected to the Gateway box. Among the various connectors, only one was compatible with the Codemate scan tool, simplifying the connection process. The additional loose connector is speculated to serve as a jumper when the Gateway box connector is disconnected.
The Codemate #94008 car OBDII reader PCM functioned as described in its instructions, successfully clearing the code 44. While the root cause of the knock sensor malfunction may or may not be entirely resolved, the immediate alarm issue was addressed. This experience underscores the utility of a car OBDII reader PCM in marine engine diagnostics, particularly for clearing fault codes and potentially identifying underlying problems. For anyone encountering similar knock sensor malfunctions or other engine code issues, a car OBDII reader PCM like the Codemate #94008 can be a valuable tool for DIY troubleshooting and maintenance.
