Proheat M80 - Manual (Page 27)

PROHEAT G-I PCM SERVICE MANUAL 2-6
The Coolant Pump continues to circulate coolant throughout the system.
When the coolant temperature drops below 160°F (71°C), the G-I 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.
If the PROHEAT is in Full Output, it will 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 a fault code(s) which best
represents the conditions. To reset the PROHEAT, it must be switched off
and then on again.
NOTE: Damage may occur it the fault codes are ignored and the PROHEAT is
repeatedly switched off and on without addressing the problem.
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
The ON/OFF switch lamp, timer lamp or OEM indicator (installation options)
will light after 30 seconds of contentiously receiving the signal. 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-I 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.
The Motor starts first, followed by the ignition spark, and then Fuel Shut-off
Valve opens. The Ignition Module sparks for 30 seconds during which time
the flame sensor must detect a correct flame. At the end of the Ignition cycle
the Flame Sensor checks the flame:
• If the PROHEAT detects proper flame, it enters Full Output.
• If the PROHEAT does not detect proper flame, the PROHEAT enters Cool
Down (Purge). The PROHEAT will attempt to start again moving into Pre-
check after Cool Down (Purge). If the second start cycle fails, the
PROHEAT will enter Fault Shut Down.
1. Supplemental Mode
Signal "ON"
(Engine Running)
2. Pre-Run
3. Pre-check
4. Ignition
SUPPLEMENTAL MODE (ENGINE RUNNING) 2.2.3