Access to ECM Grounds
Thread Starter
Instructor
Joined: Aug 2002
Posts: 198
Likes: 0
From: Yucaipa CA
Access to ECM Grounds
I've experienced some intermittant electrical problems in my '90 L98 that I think may be related to grounding. The manual suggests cleaning the ECM grounds. They appear to be located at bellhousing bolts at each side of the engine just behind the valve covers. Does anyone have a suggestion on how best to access, remove and clean the grounds. The biggest question is access i.e., remove something or jack it up and access from the underside?
I've already cleaned the connections on B+ stud located below the ECM and that cleared up most of my problems.
I've already cleaned the connections on B+ stud located below the ECM and that cleared up most of my problems.
Instructor
Joined: May 2003
Posts: 183
Likes: 0
From: San Jose CA
Re: Access to ECM Grounds (cash's90)
Believe it or not, on a 90 the ECM quad driver grounds to the injectors are connected to the heater blower ground. Its the black ground wire to the chassis under the AC line valves just in front of the heater box. Clean off corrossion, sand frame paint and reconnect.
Larry
Larry
Thread Starter
Instructor
Joined: Aug 2002
Posts: 198
Likes: 0
From: Yucaipa CA
Re: Access to ECM Grounds (cash's90)
I cleaned all of the grounds on the engine compartment frame rails. I also applied Permatex di-electric (corrosion protection) grease before remaking the grounds. My problem, that exibited itself as a rough idle (miss) accompanied by a negative battery charge rate when my blinkers were operating is now history. I also fixed my SIR problem i.e., the Infl Rest and seat belt warning lights would remain lit, by cleaning away the corrosion under my left an right SIR sensors and applying the same grease.
Thank you forum members that provided the guidance to do these fixes.
Thank you forum members that provided the guidance to do these fixes.
