PIP4869C

File in Section:
Service Bulletin
Bulletin No.:
Date:
PIP4869C
September, 2013
PRELIMINARY INFORMATION
Subject:
(EREV) Reduced Propulsion Power While Driving In Mountains
Models:
2011-2014 Chevrolet Volt
2012-2014 Opel Ampera
This PI was superseded to update the model list. Please discard PIP4869B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
A common DIC message seen by customers driving in the mountains is “Propulsion Power is Reduced.” It is
recommended that customers enter Mountain Mode on the Volt when the vehicle has a full charge if their travel plans
involve mountainous driving before the next charge event. This message may appear while severe highway grades,
even in Mountain Mode, such as driving on Interstate 70 in Colorado. This is considered normal operation.
It is possible that this message could appear in Normal or Sport mode in non-mountainous terrain, typically with
aggressive driving. When this message appears with aggressive driving, the battery reserve has been depleted.
This message may also appear on startup if the battery is at or below -15 degrees C (5 degrees F), possibly from the
vehicle sitting outside unplugged in the winter. This will be accompanied by higher engine speeds to compensate for
the low battery power.
Important: This message comes on any time the battery is reporting less than 35kW of power available for any
reason. This message will NOT require service by a dealer unless the Propulsion Power Reduced message is
accompanied by a Malfunction Indicator Light (Check Engine Light).
Recommendation/Instructions
Below is an explanation of Mountain mode that goes beyond the owner’s manual.
MOUNTAIN MODE
If your destination takes you over mountain passes in extended range driving, Volt engineers created
Mountain Mode.
To enter Mountain Mode, press the Drive Mode button three times after you unplug your Volt or 20 - 25 minutes
before you start climbing the grade.
Mountain Mode reserves some battery charge to use later during the climb. If you enter Mountain Mode below 4
bars of battery charge, the engine will run at a higher speed to build the battery buffer.
If you enter Mountain Mode above 4 bars of battery charge, the estimated electric range will adjust accordingly.
If Mountain Mode is not selected in these severe conditions, you may experience reduced propulsion power and
higher engine speed.
The Volt will continue to drive, but the vehicle speed may be reduced until the engine can recover the battery state of
charge to a normal level.
Each time you power on your Volt, it will return to Normal Mode, which maintains a smaller battery buffer suitable for
normal driving.
WHEN TO USE MOUNTAIN MODE
Mountain Mode should be selected at the beginning of the drive; ideally as the vehicle is unplugged from charging. If
a trip through the mountains or very hilly terrain is planned, Mountain Mode should be selected as early as possible
(at least 20-25 minutes before reaching the bottom of the mountain). This will ensure that vehicle performance will
not be affected by mountainous terrain.
WHAT TO EXPECT ONCE MOUNTAIN MODE IS SELECTED
After Mountain Mode is engaged the following vehicle operation should be expected:
When Mountain Mode is
Engaged
Battery Charge Level
Expected Engine Operation
Vehicle Performance
Characteristics
After a full charge before
shifting out of park
Full or close to full
No engine operation until EV
range is depleted
Vehicle performance
unchanged. Estimated EV
range decrease
While driving
Half battery
No engine operation until EV
range is depleted
Vehicle performance
unchanged. Estimated EV
range decrease
While driving
Low battery (less than 4 bars)
Engine will start soon after
Mountain Mode is engaged
Engine may run aggressively
to build battery buffer*
Engine will run aggressively
to build battery buffer
In cases when the vehicle is
already climbing grades the
vehicle may slow down and a
message stating “Propulsion
Power Reduced” will be
displayed to the driver*
Engine will run aggressively
to climb grades
In cases when the vehicle is
already climbing grades the
vehicle may slow down and a
message stating “Propulsion
Power Reduced” will be
displayed to the driver*
While driving
Not selected
Zero battery charge/range
extended mode
Zero battery charge/range
extended mode
Note: Driver may receive the “Propulsion Power Reduced” message in any mountainous terrain when an
appropriate battery buffer cannot be built BEFORE reaching the grade. The ideal time to select Mountain Mode is
when the vehicle is unplugged or 20-25 minutes BEFORE reaching the bottom of the mountain.
“PROPULSION POWER REDUCED” MESSAGE
The message comes on any time the battery is reporting less than 35kW of power available for any reason.
The Propulsion Power Reduced message can occur when driving in mountainous terrain WITHOUT using Mountain
Mode. This is normal operation to protect the vehicle’s propulsion battery. The vehicle does NOT need to be taken
to a dealer unless the Propulsion Power Reduced message is accompanied by a Malfunction Indicator Light (Check
Engine Light).
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.