Proheat X45–School Bus - Manual (Page 59)

PROHEAT INSTALLATION & SERVICE 5-2
The ON/OFF switch (or Timer) lamp and the PCM “ON” LED will light. In addition,
the Hour Meter (Auxiliary Output) will be powered. The PROHEAT goes to
“Precheck”.
EXAMPLE PROHEAT BEHAVIOR ERROR – CODE 01 5.0.2
1. Switch “ON”
Standard
Mode Signal
The PCM performs a short diagnostic cycle. This takes several seconds
checking components for proper ranges, checking for the presence of a
flame, short-circuits and open circuits. If there are no errors indicated, the
PROHEAT goes to “Ignition”.
2. Pre-check
The blower starts first, followed by the coolant pump, ignition spark, air
compressor and fuel pump. The ignition electrode sparks for 60 seconds.
3. Ignition
After two consecutive Code 01 errors, the PROHEAT goes into a hold state.
No further start attempts will be made. Code 01 will be displayed
continuously and the PCM LED “ON” light will turn “OFF.” In addition, the
Hour Meter (Auxiliary Output) will shut off.
The switch, timer red manual light or OEM indicator light will continue to flash
once, pause, flash and repeat.
NOTE: In order to restart the heater turn the switch “OFF” and back “ON”.
6. Hold State
The PROHEAT always restarts after one error detection (except for Codes 13
and 14). After the 3 minute Cool Down (Purge), the PROHEAT will go through
Precheck, Ignition and the Error Detection – Cool Down (Purge) cycle one
more time.
5. Steps 1 to 4
are Repeated
If the flame sensor did not “see” a flame in 60 seconds after entering
ignition, the air compressor and fuel pump shut off immediately. The blower
and coolant pump continue to run.
Code 01 will be displayed alternating with Pu. There will be one flash, pause
and then one flash repeating on the switch, timer red manual light or OEM
indicator light. After 3 minutes, the blower stops and the PROHEAT attempts
to start again.
NOTE: Codes 13 and 14 will not cause the heater to shut down. The PROHEAT
reports the error and continues to run.
4. Error
Detection –
Purge
The following is an example of an X45 PROHEAT behavior during an error.
The following example shows the sequence of events when the PROHEAT is
switch “ON” in the Standard Mode (similar for Preheat and Supplemental
Modes). This sequence of events occurs for Codes 01 through 12. Codes 13
and 14 do not put the heater into Cool Down (Purge) mode or shut down the
PROHEAT; rather, the PROHEAT reports the error and continues to run.