Electric Powertrain Cooling: Diagnosis Ford Focus III

Inspection and Verification

Note. The engine cooling system is filled with Motorcraft® Orange Antifreeze/Coolant. Do not mix coolant types. Mixing coolant types degrades the corrosion protection of the coolant. Failure to follow these instructions may result in powertrain or cooling system damage.

Note. During normal vehicle operation, Motorcraft® Orange Antifreeze/Coolant may change color from orange to pink or light red. As long as the coolant is clear and uncontaminated, this color change does not indicate the coolant has degraded nor does it require the coolant to be drained, the system to be flushed, or the coolant to be replaced.

1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION CHART Mechanical Electrical Coolant leak(s) Coolant level Air in system Gaskets/seals Hose(s)/hose joints Degas bottle cap and seal Degas bottle Radiator Coolant pumps Diverter valves Coolant filter High voltage batteries High voltage battery coolant warmer High voltage battery coolant chiller Fuse(s) Relay(s) Wiring harness Electrical connector(s) Cooling fan motor Coolant pumps Diverter valves ECT sensor PCM
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
4. Inspect the coolant condition in the following sequence: Inspect the coolant appearance. Discoloration may indicate that incorrect coolant may have been added to the system. Use of incorrect (green or yellow in color) coolant degrades the corrosion protection of Motorcraft® Orange Antifreeze/Coolant. Addition of Motorcraft® Specialty Green Engine Coolant may cause the color to appear to be a murky green-brown color. The addition of Motorcraft® Premium Gold Coolant, however, may not change the color or appearance of the orange colored coolant. Detection of contamination with Premium Gold Engine Coolant is determined by the presence of nitrite. If contamination with Motorcraft® Premium Gold Engine Coolant is suspected, test the coolant with the 3-Way HD Antifreeze Coolant Test Kit. Follow the nitrite testing directions in the kit to determine if nitrite is present in the system. If nitrite is present in the system, replace the coolant. REFER to: «COOLING SYSTEM FLUSHING»(ref-566956-S03834043612013071700000) (303-03 Electric Powertrain Cooling, General Procedures). A darker orange with the presence of debris could indicate a commercially available stop leak may have been used and could result in loss of coolant flow to critical parts of the engine. If stop leak is present in the coolant sample, replace the coolant. REFER to: «COOLING SYSTEM FLUSHING»(ref-566956-S03834043612013071700000) (303-03 Electric Powertrain Cooling, General Procedures). A light or reddish brown color indicates that rust may be present in the cooling system. Replace the coolant. REFER to: «COOLING SYSTEM FLUSHING»(ref-566956-S03834043612013071700000) (303-03 Electric Powertrain Cooling, General Procedures). If the powertrain coolant appearance is acceptable, test the powertrain coolant freezing point range with the Coolant/Battery Refractometer. The freezing point should be in the range -50°C to -26°C (-58°F to -15°F). If the vehicle is driven in cold climates less than -37°C (-34°F), it may be necessary to increase the coolant concentration to get adequate freeze protection. Recommended coolant concentration is 48/52 to 50/50 engine coolant to distilled water. Maximum coolant concentration is 60/40 for cold weather areas. Minimum coolant concentration is 40/60 for warm weather areas. Adjust coolant range and level if necessary: If coolant is low, add Motorcraft® Orange Antifreeze/Coolant Prediluted. If the engine coolant tests too weak, remove some of the engine coolant and add Motorcraft® Orange Antifreeze/Coolant Concentrated until the readings are within acceptable levels. If the engine coolant tests strong, remove some of the engine coolant and add distilled water until the readings are within acceptable levels.
5. If the cause is not visually evident, verify the symptom and refer to the Symptom Chart below.

SYMPTOM CHART

Scheme 87

Scheme 88

Scheme 89

Scheme 90

1. Install the D-Gas Adapter and the Radiator Tester to the disconnected hose.
2. Remove the hose pinch pliers.
3. NOTE: Do not pressurize the cooling system beyond the 138 kPa (20 psi) or cooling system components may be damaged. NOTE: If the plunger of the pressure tester is pressed too fast, an erroneous pressure reading will result. Slowly press the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained. If the pressure reading exceeds 138 kPa (20 psi), install a new pressure relief cap.
4. If the system does not hold pressure, remove the pressure relief cap and wash in clean water to dislodge all the foreign material from the gasket. Check the sealing surface in the filler neck of the degas bottle for nicks or cuts. Install the pressure relief cap.
5. Pressurize the engine cooling system as described in Step 4. Observe the gauge reading for approximately 2 minutes. Pressure should not drop during this time. If the pressure drops within this time, inspect for leaks and repair as necessary.
6. If no leaks are found and the pressure drops. the pressure relief cap may be leaking. Install a new pressure relief cap and retest the system.
7. If no leaks are found after a new pressure relief cap is installed, and the pressure drops, the leak may be internal to the High voltage batteries. Remove the battery drain plugs.
8. Release the system pressure by loosening the pressure relief cap. Check the coolant level and adjust as necessary.

Radiator Leak Test, Removed From Vehicle

Note. Never leak test an aluminum radiator in the same water that copper/brass radiators are tested in. Flux and caustic cleaners may be present in the cleaning tank and they will damage aluminum radiators.

Note. Clean the radiator before leak testing to avoid contamination of tank.

Leak test the radiator in clean water with air pressurized to 138 kPa (20 psi).