2018-Navigator-Owners-Manual

Maintenance

Engine Coolant Temperature Management (If Equipped) WARNING

You may notice a reduction in vehicle speed caused by reduced engine power in order to manage the engine coolant temperature. Your vehicle may enter this mode if certain high-temperature and high-load conditions take place. The amount of speed reduction depends on vehicle loading, grade and ambient temperature. If this occurs, there is no need to stop your vehicle. You can continue to drive. The air conditioning may automatically turn on and off during severe operating conditions to protect the engine from overheating. When the coolant temperature decreases to the normal operating temperature, the air conditioning turns on. If the coolant temperature gauge moves fully into the red zone, or if the coolant temperature warning or service engine soon messages appear in your information display, do the following: 1. Stop your vehicle as soon as it is safe to do so. Fully apply the parking brake, shift into park (P) or neutral (N).

2. Leave the engine running until the coolant temperature gauge needle returns to the normal position. After several minutes, if the temperature does not drop, follow the remaining steps. 3. Switch the engine off and wait for it to cool. Check the coolant level. 4. If the coolant level is at or below the minimum mark, add prediluted coolant immediately. 5. If the coolant level is normal, restart the engine and continue. AUTOMATIC TRANSMISSION FLUID CHECK If required, have an authorized dealer check and change the transmission fluid at the correct service interval. See Scheduled Maintenance (page 552). The automatic transmission does not have a transmission fluid dipstick.

To reduce the risk of crash and injury, be prepared that the vehicle speed may reduce and the vehicle may not be able to accelerate with full power until the coolant temperature reduces. If you tow a trailer with your vehicle, the engine may temporarily reach a higher temperature during severe operating conditions, for example ascending a long or steep grade in high ambient temperatures. At this time, you may notice the coolant temperature gauge moves toward the red zone and a message may appear in the information display.

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Navigator (TB9) Canada/United States of America, enUSA, Edition date: 201708, First Printing