6/Service
6-9 6-9
Error Codes
E1.1 Heater Control Circuit Failure
As part of the Power Up Self Tests (PUSTs), a routine checks the function of the solid
state relay. This relay controls the heater power. The relay is turned off, and the heat
is checked using the heater current sense circuit. The heat should be off (no current).
The relay is then turned on, and the heat should be on. If this is not successful, this
error is displayed. Check resistances to the following table:
Pins
Resistance
5 - 10
0 - 10
1 - 5
350 - 440
3 -5
85 - 110
If the resistance falls out side of the ranges
listed in the table, replace the heater assembly.
If the resistances are within the listed ranges,
replace the microcontroller or the printed circuit
board.
E1.2 ROM Checksum Error
As part of the PUSTs, a routine performs a checksum on the ROM (code) part of the
microcontroller. This checksum merely adds each byte of the ROM to form a resulting
word. The last two bytes are excluded from this sum. It then adds the last word (two
bytes) to the checksum word, and the result should be zero. If it is not, this error is
displayed. Replace the microcontroller if this error appears.
E1.3 RAM Test Failure
As part of the PUSTs, a routine performs a RAM (data memory) test by writing and
reading various patterns to and from RAM. If any location does not pass this test, this
error is displayed. Replace the microcontroller if this error appears.
E1.4 Watchdog Circuit Failure
As part of the PUSTs, a routine tests the watchdog circuit. This circuit is a timer that
needs a pulse from the microcontroller periodically. If this pulse fails to come in to the
circuit, the circuit will interrupt the microcontroller, turn off the heat, and produce a
system failure. During this test, the microcontroller pulses the watchdog circuit and
verifies that the interrupt does not appear. It then stops pulsing the watchdog and
verifies that the interrupt does appear. If this fails, this error is displayed. Replace the
microcontroller. If the problem persists, replace the board.
E2.1 Function Execution Error
As part of the On-Line Self Tests (OLSTs), a routine tests a software variable
that is modified by the various software functions in the code. If the variable is
not the correct value, the execution of functions did not occur correctly, and
this error is displayed. Replace the microcontroller.
E2.2 Analog-to-Digital Converter Failure
As part of the OLSTs, a routine tests the analog-to-digital converter (ADC) timing. The
ADC must convert within a specific number of machine cycles on the microcontroller. If
this test fails, this error is displayed. Replace the microcontroller.
Summary of Contents for Ohio Care Plus
Page 20: ...2 General Information 2 4 2 4 Notes...
Page 24: ...4 Using the Servo controlled Humidifier 4 2 4 1 Notes...
Page 46: ...6 Service 6 18 6 18...
Page 53: ...8 Schematics 8 1 Figure 8 1 Wiring Diagram Servo controlled Humidifier 8 Schematics CI 18 059...
Page 55: ...8 Schematics 8 3 Figure 8 3 Digital section of the Control Display Board Assembly CI 18 061...
Page 56: ...8 Schematics 8 4 Figure 8 4 Analog section of the Control Display Board Assembly CI 18 062...
Page 58: ...8 Schematics 8 6 Figure 8 6 Display section of the Control Display Board Assembly CI 18 064...
Page 67: ......
