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Kenny Z.
Kenny Z., Ford Senior Master Tech
Category: Ford
Satisfied Customers: 5449
Experience:  Auto Trans, Drivability and Electrical Specialist
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I have a 2004 f-150 heritage, theft light flashing with key

Customer Question

Hi Im Dave, I have a 2004 f-150 heritage, theft light flashing with key on wont start does crank odometer reads ------ andscan tool will not communicate.....any suggestions?
Submitted: 1 year ago.
Category: Ford
Expert:  Kenny Z. replied 1 year ago.

Hello, my name is***** and thanks for your question. It sounds like the PCM is offline. Does the check engine light come on when you turn the key from off to run? If so does it go out when cranking the engine or does it stay on when cranking the engine? Also what engine is in the truck?

Customer: replied 1 year ago.
the check engine light comes on and ys the check engine light goes out while cranking the engine, it is a 4.6 (w) engine
Expert:  Kenny Z. replied 1 year ago.

Ok, that means the PCM is on line and receiving crank sensor signal. Is there 12 volts present on pin 16 in the data link connector? Link below for connector pin view. The dashes in the odometer means the cluster and the PCM are not communicating. If the theft light is flashing rapidly then either the cluster is not seeing the key signal or the PCM is not receiving a valid ok to start signal from the cluster. The cluster interrogates the key code and gives an all ok signal to the PCM. The PCM will not allow the engine to start without receiving that signal. Seeing how the odometer is displaying dashes and the theft light is flashing might be indicating a possible cluster failure. Does the rest of the cluster operate normally?

Customer: replied 1 year ago.
the rest of the cluster operates correctly and the 16 pin connector has 12 volts but scan tool will not communicate
Expert:  Kenny Z. replied 1 year ago.

Have you tried a different scanner? I have attached the pinpoint test below for no communication. This test leads to PCM replacement quickly and is often incorrect. In reality you need a Ford IDS scanner which can perform network diagnostics and can ping all of the modules on the network and also pull DTC's and data from the cluster. Without having an IDS scanner the below test is all that is available. Most generic scanner and code readers do not have network diagnostic capabilities and cannot communicate with proprietary modules, usually just limited to PCM.

Expert:  Kenny Z. replied 1 year ago.

If you need more help, please use the reply tab to continue our conversation. If you do not require further assistance, kindly rate my service as you see fit. Rating does not close the question if you have follow up questions. Thanks!