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Hi Everyone...This is my first post here...it looks like a great community!
We have a 2007 E350 Super Duty Cut-Away Van. It has an Airbag Light, which blinks Code 12.
I've found enough information to begin troubleshooting the Code 12, which indicates low voltage to the RCM.
I've checked power all the way from the battery to the fuse and the RCM connector (Red/White wire), and am getting 12V at every point including the connector at the RCM. So it appears to be receiving nominal battery voltage.
I found a troubleshooting guide that says the next check is to make sure the RCM ground is good. But the guide is for a different year, and the wire colors don't match.
Does anyone have a wiring diagram that would tell me the Pin # or wire color for Ground at the RCM connector?
Does anyone have experience with the Instrument Cluster causing the Code 12 problem? We've had a few cases where all the gauges go to zero and then right back to normal. I understand this is a common problem with Super Duty instrument clusters. The troubleshooting guide said to check the Instrument Cluster connection, but again the wire colors and pinouts don't match my vehicle.
Looking in the factory service manual for you specific vehicle, it explicitly says to replace the RCM (airbag control module) for an LFC 12. No troubleshooting steps are given, it says just replace it. Chances are, you might find someone on eBay who can "fix" it so it is usable again.
1) The RCM ground wire, and 2) The RCM Indicator Lamp wire that goes to the instrument cluster.
Probably a rabbit trail, but feel free to go on down it.
1. Black/Light Green. Goes to ground G201 located under the driver's seat.
2. Black/Yellow. There's nothing wrong with that wire since it is able to communicate the LFC to the IC.
There's a good chance the RCM is bad. Code 12 is for low voltage, but the input pin reads nominal voltage. So it could be an internal failure.
I'll look at options. Is an RCM tied to VIN, or can I just get any used one?
We've also seen the gauge cluster drop out a few times. I think I'll change that first to be sure that's not the problem. Reason I'm wondering is that the Airbag Indicator Lamp is a little dimmer than the other lights. I'm wondering if the voltage on that circuit is low due to an instrument cluster failure of some kind.
I think I'm going to try sending both the instrument cluster and the RCM to a rebuild house and get both fixed and tested at the same time...that should solve both my problems.
I'll probably be back with other questions...but for now I think I'm all set on this topic.