Ford Hybrid A/C

Face it. Working on hybrid vehicles can make some technicians nervous. Even though the systems on a hybrid may be used somewhat differently, they are not new and most technicians will have no problem working on them.

Recently I got a call on a 2008 Escape Hybrid with an A/C issue. So what is different on the hybrid A/C? Actually there are only a couple of small differences on the Escape hybrid A/C system versus the Escape gas.

First, the hybrid battery uses a climate control system. This is not a new system. Ford simply used an auxiliary rear A/C system to blow air onto the hybrid battery when it gets too warm. If you have worked on an auxiliary A/C system on a van or other SUV, you won’t have any trouble working on this part of the hybrid system.

Second, a solenoid blocks Freon to the passenger compartment. Since there may be times the customer does not want A/C but the battery may need to be cooled, the solenoid is allowed to close to prevent Freon from getting to the evaporator core.

OK, those are the only significant differences, but where to begin a diagnosis of poor cooling? This particular Escape cooled but not very well. In 80 degree temperatures it would only cool to around 60 degrees. As with any vehicle, I like to start with a set of pressure gauges. In this case, the pressure on the low side was 35 to 40; the high side was 180 to 200. These are good pressures. So next I checked the temperature going in and out of the evaporator core and the expansion valve. Remember there is an extra component on this vehicle, the passenger shutoff solenoid (See photo).

If this solenoid is the problem you should notice a temperature difference on each side. If the solenoid has something stuck in it, unplug it and then plug it back in several times. See if the temperature drops to normal. In this case, a stuck solenoid was the issue. It is important to note that a careful inspection for desiccant material should be performed. If any is found, the accumulator, solenoid and expansion valve should be replaced and the evaporator, condenser and lines should be flushed.

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