Experiencing a frustrating no-start issue with your 2002 CLK 320 Mercedes-Benz? It’s a common headache: you turn the key, the instrument cluster lights up normally, but the engine refuses to crank or start. This problem can start intermittently, becoming more frequent over time, turning from a weekly annoyance to a daily frustration. Before you rush to expensive repairs, consider a simple DIY fix that might save you hundreds of dollars: checking and cleaning your car’s relays.
Many CLK 320 owners have encountered this exact scenario and found a surprisingly straightforward solution. The issue often lies within the relays located in the driver’s side hood module, also known as the SAM (Signal Acquisition and Actuation Module). These small components are crucial for various electrical functions, including starting your engine. Over time, the contacts inside these relays can corrode or develop poor connections, leading to intermittent failures.
One of the key relays to examine is the starter relay, often labeled “S”. Another important relay is the “R” relay, also known as the terminal 87 relay, which is engine-related. While the starter relay might appear to have good contacts, intermittent issues can still occur. The “R” relay is frequently found to have corroded contacts, causing intermittent starting problems.
The DIY fix involves carefully disassembling these relays and inspecting the internal contacts. With fine sandpaper (contact paper), gently clean the contacts to remove any corrosion and improve conductivity. This simple cleaning process can often restore the relays to full functionality, resolving your no-start issue.
Beyond the relays, another often-overlooked area is the key fob and its receiver in the car. Cleaning the infrared lens on both the key and the receiver can improve communication. Disassembling the key fob to clean its internal components and replacing the batteries are also beneficial steps. These actions can address potential issues with key signal transmission, which can sometimes contribute to starting problems.
By addressing these simple points – relay maintenance and key/receiver cleaning – many CLK 320 owners have successfully resolved their no-start issues. To ensure long-term reliability, consider replacing the “R” and “S” relays. Genuine Mercedes-Benz parts are recommended for optimal performance and compatibility. The part numbers are:
- A 002 542 26 19 for the “R” relay (terminal 87 relay, motor)
- A 002 542 92 19 for the “S” relay (starter relay)
Purchasing these relays from Mercedes-Benz can cost around $34 and $18 respectively, making the total repair cost approximately $70 – a fraction of what dealership troubleshooting and extensive parts replacements might cost.
Before investing in expensive diagnostic procedures and part replacements, especially when faced with a no-start issue in your 2002 CLK 320 Mercedes-Benz, consider this simple and cost-effective DIY approach. Cleaning or replacing your relays and maintaining your key fob might be the only steps needed to get your car back on the road reliably. This proactive approach can save you significant time and money, highlighting the importance of checking simpler solutions first before assuming more complex problems.
