No Crank

Lesage Technician Michigan Posted   Latest   Edited  
Updated
Driveability
Electrical
2011 Ford F-250 Super Duty XLT 6.2L (6) 6-spd (6R140) — 1FT7W2B62BEC54177
No Crank / No Start

The truck has been hit on front right side and repaired according to the owner. During the process of diagnosing turn signal issues I found out that the bcm opens up/separates when trying to unplug connectors. After messing with bcm the truck wouldn't crank. This happened twice. I had a code related to “bcm run/start relay output control” or something like that. Used the scanner to activate the relay and the truck started. Now I don't have the dtc anymore but no crank. I'm going to replace the BCM because the FR turn signal blinks with test light in the socket but stops after the light bulb is inserted in the socket, the BCM stop sending the signal to the bulb. 

But why is the PCM not doing its job turning the starter relay on? Because according to the diagram it controls both pos and neg side if the relay coil.

There is no PCM output at pin 37 (strt rly ctr+) when cranking. Pin 7(Strt rly ctr-) output is present.

IG switch input to the PCM and BCM are ok.

Is the ACM starter relay control necessary or is it just an alternative based on vehicle option? 

0
Chris Technical Support Specialist
New York
Chris
 

The ACM receives an input on the start circuit to mute the audio during cranking to prevent popping in the speakers. You can disconnect the radio but it is not likely related to your concern.

+1
Ð Awarded
Lesage Technician
Michigan
Lesage
 

Ah ok. According to the diagram it's the PCM that sends the start signal to the ACM via the starter relay control+ pin 37. If the BCM has no input in the starting process, then I'm gonna swap the PCM with a used one.

0
Ð Awarded
Brandon Technician
Maine
Brandon
   

I agree had one having same issue starting.. have you check pcm for issues regarding receiving and sending request to start? You may have 2 separate issues as far as the turn signal have you load tested wires?

0
Ð Awarded
Lesage Technician
Michigan
Lesage
   

From the diagram, all inputs to PCM and BCM are there. I did have a B2532, but that might have been from me activating the run/start output control from the scanner to start and move the truck. According to alldata, Bcm activates the run/start relay and through the relay sends voltage signal to the PCM on pin 42. All of this happen in the run/start position. Tested that input and it's also…

0
Ð Awarded
Lesage Technician
Michigan
Lesage
 

Yes I have load tested by connecting a headlamp bulb to the ground wire and the power wire to the turn sig wire and then to the park light wire. Then used the power probe to supply battery voltage from the disconnect bcm connector. They all passed.

0
Ð Awarded
Alexander Diagnostician
New Jersey
Alexander
 

I believe once you replace and program the bcm. You should be on the clear. It seems you have a fractured bcm and hat would cause intermitteby issues

+1
Ð Awarded
Agree
Lesage Technician
Michigan
Lesage
 

I'll start there but I think I have 2 separate issues. Owner said he had issues starting before but “once started it was good”. I had to pry that from him. Don't understand why they think hiding things will make it cheaper.

0
Ð Awarded
Timothy Owner/Technician
Wisconsin
Timothy
 

The diagram shows a fairly simple system. The BCM is NOT involved here, as far as the actual crank circuits are concerned, only the PCM the start relay and the ignition switch. Should have 12V at Pin 16 on C1232B at the PCM from the ignition switch. If all that's good, then the last thing to check is theft, and you'd have codes. No codes? Then the PCM has failed. Not all that uncommon.

0
Ð Awarded
Lesage Technician
Michigan
Lesage Update
 

Hello all. I took a break from this truck to focus on other vehicles. Couldn't locate the correct bcm p/n in the used market, but finally got one. I still have the same issues. Perhaps the used bcm I got is no good either. Brand new is not available from Ford, no eta. For the FR turn signal, I get no output from the BCM at all. I think the truck has ed bulbs in the back. I'll remove them and…

0
Update Ð Awarded