FEH - No Start

[GaryG]

Well, I've started two other threads because of having to have my FEH towed to the dealership because it would not start. Thought I'd better start a new thread with a better title so people could find the answer easier as it relates to "will not start".

Towing (3 times), repair hours, a 12V battery and $36 in relays cost me ~$1250 and 10 days without a vehicle. I feel it's important that you learn from my experiences and save yourself some money and a big headache in the future if it happens to your FEH/MMH. The Hybrid Tech and Ford's Hotline say this was the first time they've seen 3 main relays go bad like this, and they wanted details of any thing I was doing that could caused the relays to go bad. Nothing I told them explained what the cause was, so they gave me a spare relay so if it happens again, I could change it myself and get started again. There are 5 relays, and are all the same and cost $12 each. They are located in the Battery Junction Box behind the engine air filter and can be changed without tools in seconds.

Take off the cover and you will see the relays on the left and fuses and stuff on the right.

From the back to the front in order are Relays 001-005, here's what they are:

001 Relay - Power Sustain Relay (mine was bad)

002 Relay - PCM power relay (mine was bad)

003 Relay - Injector relay ( mine was bad)

004 Relay - Heater Pump relay

005 Relay - M/E coolant pump relay

The power sustain relay controls charging the HV battery with the generator and regen. The PCM power relay powers the PCM and the Injector relay can prevent fuel for starting as the engine turns over.

These relays can be interchanged, but the only one safe to remove and drive the vehicle is the Heater pump relay. The heater pump only comes on in EV while the belt driven coolant pump stops. I may pull that relay to save energy and keep the engine hot in EV anyway if I don't get a warning light. You can also turn the climate control system off like I do to keep the heater pump off in EV.

If your engine will not start, you may want to plan a head and get at least one spare relay to try to trouble shoot to get going again.

GaryG