Error
Location
Type
Description
Cause
Solution
Hose portion
exposed to an
excessive heat
source, like hot
sun or coiled
hose, can pass
fluid more than
27°F (15°C) over
hose temperature
setting to the FTS.
Shade exposed hose from
hot sun or expose FTS to
same environment when
at rest. Uncoil entire hose
before heating to avoid
self-heating.
T4DH
Hose
High Temperature
Hose
Setting the A or
B setpoint much
higher than hose
setpoint can cause
fluid more than
27°F (15°C) over
hose temperature
setting to reach the
FTS.
Increase hose setpoint
so it is closer to A and B
setpoints.
Overtemperature
switch sensed a
fluid temperature
above 230°F
(110°C).
Heater was delivered too
much power, causing the
overtemperature switch to
open. RTD is not reading
properly. After the heater
cools down, replace RTD.
Switch closes and the error
can be cleared when the
heater temperature falls
below 190°F (87°C).
Broken or loose
overtemperature
switch
cable/connection.
If heater is not actually
over temperature, check
all wiring and connections
between the TCM and the
overtemperature switches.
T4EA
Heater A
High Temperature
Switch A
Overtemperature
switch failed in the
open position.
Replace overtemperature
switch.
28
333024A
