MACS Monthly Newsletter - 2019 - OCT6

acdelcotds.com

to prevent icing. Any greater increase would be noticeable and
probably dissatisfy those who want the feel of very cold air on
their faces.
This particular problem is not unique to the Colorado and
Canyon pickups. Many vehicles over the years that have variable displacement compressors may report icing under specific
conditions. Steady cruising speed with high humidity and low
blower speed plus low cooling load can create the same issue in
many locations. The simplest approach is to tell the customer to
raise the blower speed and/or edge the temperature control off
maximum cold. Most people will find a setting that provides
enough "cold face" comfort.
GM had a similar issue with 2017-on full-size vans (Chevy
Express/GMC Savana), in which the air from the A/C registers would change intermittently from icy cold to warm in hot
ambient temperatures. In this case, the issue is control software,
and GM released a new program to fix the issue. So once again,
"read first" before you decide to do something.
Some years ago, Nissans with variable displacement compressors, using an internal all-mechanical control valve, were
prone to this form of evaporator icing, particularly pre-2010 Altimas. It was especially prevalent in cruising at low cooling load
and Nissan eventually released a recalibrated compressor for
those applications. ■

Figure 9: Control head of GM mid-size Colorado/Canyon
pickups with manual HVAC controls. Setting at maximum cold and low blower could lead to evaporator freezeup in humid weather.
must be enough people in the Gulf Coast states who have raised
the question. Because GM has released a new program for the
HVAC module. What it does is raise minimum evaporator outlet temperature a couple of degrees, which should be enough

Does This Sound Familiar: The Refrigerant Label That Isn't There
so that's what he installed. He started up the system and both
sides pressures were erratic, with the high side going too high.

alldata.com

alldata.com

We've talked about the problem of missing refrigerant labels,
particularly common when the car comes in from a body shop.
In this case, a 2006 Volvo XC70 with the 2.5-liter four cylinder,
there was a lot that was wrong. Because the car had a front end
hit, there was a new condenser installed by the body shop. The
service technician was told the capacity was 2.2 pounds (35 oz.),

Figure 11: But in fact, if you carefully go through this aftermarket service information system there is a refrigerant
capacities chart. Just read it carefully as the model groupings could confuse you.

Figure 10: Volvo service information implies that to get the
specification for refrigerant capacity, you have to use the
underhood decal. alldata.com

October 2019

6

MACS Service Reports



http://www.acdelcotds.com http://www.alldata.com http://www.alldata.com http://www.alldata.com

MACS Monthly Newsletter - 2019

Table of Contents for the Digital Edition of MACS Monthly Newsletter - 2019

MACS Monthly Newsletter - 2019 - JAN1
MACS Monthly Newsletter - 2019 - JAN2
MACS Monthly Newsletter - 2019 - JAN3
MACS Monthly Newsletter - 2019 - JAN4
MACS Monthly Newsletter - 2019 - JAN5
MACS Monthly Newsletter - 2019 - JAN6
MACS Monthly Newsletter - 2019 - JAN7
MACS Monthly Newsletter - 2019 - JAN8
MACS Monthly Newsletter - 2019 - FEB1
MACS Monthly Newsletter - 2019 - FEB2
MACS Monthly Newsletter - 2019 - FEB3
MACS Monthly Newsletter - 2019 - FEB4
MACS Monthly Newsletter - 2019 - FEB5
MACS Monthly Newsletter - 2019 - FEB6
MACS Monthly Newsletter - 2019 - FEB7
MACS Monthly Newsletter - 2019 - FEB8
MACS Monthly Newsletter - 2019 - MAR1
MACS Monthly Newsletter - 2019 - MAR2
MACS Monthly Newsletter - 2019 - MAR3
MACS Monthly Newsletter - 2019 - MAR4
MACS Monthly Newsletter - 2019 - MAR5
MACS Monthly Newsletter - 2019 - MAR6
MACS Monthly Newsletter - 2019 - MAR7
MACS Monthly Newsletter - 2019 - MAR8
MACS Monthly Newsletter - 2019 - APR1
MACS Monthly Newsletter - 2019 - APR2
MACS Monthly Newsletter - 2019 - APR3
MACS Monthly Newsletter - 2019 - APR4
MACS Monthly Newsletter - 2019 - APR5
MACS Monthly Newsletter - 2019 - APR6
MACS Monthly Newsletter - 2019 - APR7
MACS Monthly Newsletter - 2019 - APR8
MACS Monthly Newsletter - 2019 - MAY1
MACS Monthly Newsletter - 2019 - MAY2
MACS Monthly Newsletter - 2019 - MAY3
MACS Monthly Newsletter - 2019 - MAY4
MACS Monthly Newsletter - 2019 - MAY5
MACS Monthly Newsletter - 2019 - MAY6
MACS Monthly Newsletter - 2019 - MAY7
MACS Monthly Newsletter - 2019 - MAY8
MACS Monthly Newsletter - 2019 - JUN1
MACS Monthly Newsletter - 2019 - JUN2
MACS Monthly Newsletter - 2019 - JUN3
MACS Monthly Newsletter - 2019 - JUN4
MACS Monthly Newsletter - 2019 - JUN5
MACS Monthly Newsletter - 2019 - JUN6
MACS Monthly Newsletter - 2019 - JUN7
MACS Monthly Newsletter - 2019 - JUN8
MACS Monthly Newsletter - 2019 - JUL1
MACS Monthly Newsletter - 2019 - JUL2
MACS Monthly Newsletter - 2019 - JUL3
MACS Monthly Newsletter - 2019 - JUL4
MACS Monthly Newsletter - 2019 - JUL5
MACS Monthly Newsletter - 2019 - JUL6
MACS Monthly Newsletter - 2019 - JUL7
MACS Monthly Newsletter - 2019 - JUL8
MACS Monthly Newsletter - 2019 - AUG1
MACS Monthly Newsletter - 2019 - AUG2
MACS Monthly Newsletter - 2019 - AUG3
MACS Monthly Newsletter - 2019 - AUG4
MACS Monthly Newsletter - 2019 - AUG5
MACS Monthly Newsletter - 2019 - AUG6
MACS Monthly Newsletter - 2019 - AUG7
MACS Monthly Newsletter - 2019 - AUG8
MACS Monthly Newsletter - 2019 - SEP1
MACS Monthly Newsletter - 2019 - SEP2
MACS Monthly Newsletter - 2019 - SEP3
MACS Monthly Newsletter - 2019 - SEP4
MACS Monthly Newsletter - 2019 - SEP5
MACS Monthly Newsletter - 2019 - SEP6
MACS Monthly Newsletter - 2019 - SEP7
MACS Monthly Newsletter - 2019 - SEP8
MACS Monthly Newsletter - 2019 - OCT1
MACS Monthly Newsletter - 2019 - OCT2
MACS Monthly Newsletter - 2019 - OCT3
MACS Monthly Newsletter - 2019 - OCT4
MACS Monthly Newsletter - 2019 - OCT5
MACS Monthly Newsletter - 2019 - OCT6
MACS Monthly Newsletter - 2019 - OCT7
MACS Monthly Newsletter - 2019 - OCT8
MACS Monthly Newsletter - 2019 - NOV1
MACS Monthly Newsletter - 2019 - NOV2
MACS Monthly Newsletter - 2019 - NOV3
MACS Monthly Newsletter - 2019 - NOV4
MACS Monthly Newsletter - 2019 - NOV5
MACS Monthly Newsletter - 2019 - NOV6
MACS Monthly Newsletter - 2019 - NOV7
MACS Monthly Newsletter - 2019 - NOV8
MACS Monthly Newsletter - 2019 - DEC1
MACS Monthly Newsletter - 2019 - DEC2
MACS Monthly Newsletter - 2019 - DEC3
MACS Monthly Newsletter - 2019 - DEC4
MACS Monthly Newsletter - 2019 - DEC5
MACS Monthly Newsletter - 2019 - DEC6
MACS Monthly Newsletter - 2019 - DEC7
MACS Monthly Newsletter - 2019 - DEC8
https://www.nxtbook.com/nxtbooks/macs/servicereports_2022
https://www.nxtbook.com/nxtbooks/macs/servicereports_2021
https://www.nxtbook.com/nxtbooks/macs/servicereports_2020
https://www.nxtbook.com/nxtbooks/macs/servicereports_2019
https://www.nxtbook.com/nxtbooks/macs/servicereports_2018
https://www.nxtbook.com/nxtbooks/macs/servicereports_2017
https://www.nxtbook.com/nxtbooks/macs/servicereports_2016
https://www.nxtbook.com/nxtbooks/macs/servicereports_2015
https://www.nxtbookmedia.com