Proheat M125 - Manual (Page 33)

The Motor and Coolant Pump continue to operate for three minutes. After three
minutes, the Motor stops and the PROHEAT enters Standby. The PROHEAT
will Cool Down (Purge) for three reasons:
• Coolant reaches 185°F (85°C).
• A fault is detected. Go to Section 4.0 Troubleshooting and Repair, page 4-1.
• The PROHEAT is operating in Ignition or Full Output when it is switched off.
CAUTION
Always ensure that the PROHEAT is allowed to Cool Down (Purge) for a full 3
minutes. If the power is shut off without a proper Cool Down (Purge) during
Full Output, DAMAGE TO THE HEATER MAY OCCUR.
6. Standby
7. After 90 mins.
or a Momentary
Switch “OFF”
Signal
8. Fault Shut
Down
NOTE: Only the G-II PCM has an indicator light. See page C-1 for more information.
The ON/OFF switch lamp, timer lamp or OEM indicator (installation options) will
light after 30 seconds of contentiously receiving the signal. In addition, the G-
II PCM Indicator Light with turn ON GREEN. If the coolant temperature is
below 160°F (71°C) the PROHEAT enters Pre-run. If the coolant temperature is
above 160°F (71°C) the PROHEAT enters Supplemental Standby (coolant
pump off). If the coolant pump is requested on via the coolant pump input
(analog or CAN) the PROHEAT enters Standby (coolant pump on) and will
move directly to Pre-check.
The coolant pump operates for 30 seconds to circulate coolant through the
system. If the coolant temperature is above 160°F (71°C) at the end of 30
seconds, the pump shuts off and the PROHEAT returns to Supplemental Standby
(coolant pump off). If the coolant temperature remains below 160°F (71°C)
after 30 seconds, the PROHEAT goes to Pre-check (with the coolant pump on).
The G-II PCM performs self diagnosis checking sensors for correct range,
electrical components for over-load and for a flame presence. Also during the
first Pre-check, the Ignition Module sparks for five seconds to allow a service
technician to visually check for a spark. If there are no errors indicated, the
PROHEAT goes to Ignition.
1. Supplemental
Mode Signal "ON"
(Engine Running)
2. Pre-run
3. Pre-check
SUPPLEMENTAL MODE (ENGINE RUNNING) 2.3.3
The Coolant Pump continues to circulate coolant throughout the system.
When the coolant temperature drops below 150°F (65°C), the G-II PCM will
enter the cycle starting at Pre-check. The PROHEAT will continue to repeat
Steps 2 to 6 until it is switched “OFF.”
The ON/OFF switch lamp, timer lamp or OEM indicator (installation options)
will turn off. In addition, the G-II PCM Indicator Light will turn OFF.
If the PROHEAT is in Full Output, it will Cool Down (Purge) first and then shut
“OFF”. If the PROHEAT is in Standby, it will shut “OFF” immediately.
If the PROHEAT diagnostics sense a system or component fault, the PROHEAT
will shut down all components and flash diagnostic code(s) which best
represent the conditions. The flash codes will be shown on the G-II PCM
Indicator Light in RED. In addition, the ON/OFF switch lamp, timer lamp or
OEM indicator (installation options) will also flash the same code(s). To reset
the PROHEAT, it must be switched off and then on again.
NOTE: Damage may occur if the diagnostic codes are ignored and the PROHEAT
is repeatedly switched off and on without addressing the problem.
OFF
RED
5. Cool Down
(Purge)
GREEN
INDICATOR
LIGHT
2-8 PROHEAT M-SERIES G-II PCM SERVICE MANUAL