{"id":6731,"date":"2022-02-22T13:00:39","date_gmt":"2022-02-22T21:00:39","guid":{"rendered":"https:\/\/mitchell11.wpenginepowered.com\/blog\/shopconnection\/suretrack-real-fix-overcooled\/"},"modified":"2025-01-02T12:35:07","modified_gmt":"2025-01-02T20:35:07","slug":"suretrack-real-fix-overcooled","status":"publish","type":"shopconnection","link":"https:\/\/mitchell1.com\/shopconnection\/suretrack-real-fix-overcooled\/","title":{"rendered":"SureTrack Real Fix: Overcooled"},"content":{"rendered":"

\"\"<\/a>Real Fixes from the SureTrack\u00ae<\/a> expert information resource are documented issues from actual shop repair records and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is available at no additional cost in our ProDemand<\/a> product.<\/p>\n

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Electrical issues can be hard to diagnose, especially when standard testing doesn’t reveal the problem. Sometimes you have to go inch by inch through the wiring to find the cause. SureTrack community member Mlopez2008<\/strong> had a Mercedes-Benz CLK320 in their shop with a message on the dash and the cooling fan running any time the key was on. They posed the question to the community, and with the help of fellow community member Richard_C<\/strong> and others, they were able to resolve the issue quickly.<\/p>\n

The following Community Fix summarizes the interaction between members of the community that led to the solution.<\/p>\n

Vehicle<\/strong>
\n2005 Mercedes-Benz CLK320 3.2L<\/p>\n

Title<\/strong>
\nCooling fan remains on, repaired wiring harness.<\/p>\n

Complaint<\/strong>
\nCustomer states that “Coolant Service” message is displayed on instrument panel.<\/p>\n

Diagnostic Steps Performed\/Parts Replaced<\/strong>
\nConfirmed message on instrument panel. Found that the cooling fan is on full high any time the key is on. No blown fuses found. Power and ground are present. Don’t have probe to test for pulse from ECM. Got an aftermarket fan from Import Direct (Continental). Hooked it up, and the fan didn’t come on with the key, which at first I thought meant it was fixed. I attempted to activate the fan with scan tool. When doing so the fan never came on. Mercedes doesn’t give much for description and operation. I’m starting to believe there may be an ECM issue. Has anyone seen this concern?<\/p>\n

Cause<\/strong>
\nLooking through the wiring diagram I checked the wires for continuity. Probably something I should have done earlier. In any case, connector 4, Pin 39 Green\/Blue at ECM to fan connector pin 4 Green\/Blue had no continuity. I followed the harness back from the fan and just after the plastic insulator for the harness it tees off. The Green\/blue wire was chaffed and corroded about a foot and a half back from connector. Just inside the wheel well.<\/p>\n

Correction<\/strong>
\nRepaired the wiring harness by replacing corroded and chafed section. Fan now works as it should.<\/p>\n

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SureTrack\u00ae adds to the power of ProDemand\u00ae<\/a> with an exclusive combination of real-world knowledge and powerful diagnostic tools, all wrapped in an interactive community of professional technicians. Designed to help automotive shops increase accuracy and efficiency from diagnosis to completed repair, the industry’s most comprehensive repair information resource is just a few clicks away.<\/p>\n

Want more? Here’s how you can see more Real Fixes in SureTrack:<\/strong><\/p>\n