- 34 -
STEP
ACTION
YES
NO
GO TO
46.
When blower control module is completely detached from blower motor, verify with standard
ohmmeter that the resistance from each motor lead in motor plug to unpainted motor end
plate is greater than 100k ohms. Then verify motor windings are not shorted or open by
measuring resistance between each combination of pins in motor plug (there are three
different combinations, pin 1-2, pin 2-3, and pin 1-3). Resistance should be approximately
equal across each combination of pins.
47
47.
Did the motor pass the resistance check?
48
50
48.
Does blower wheel turn freely with blower control module removed?
49
50
49.
Replace blower control module. Inspect failed blower control module for water damage. If
present, find source of water and fix. Check A-coil and/or humidifier.
8
50.
Replace entire blower motor including blower control module. Inspect blower control
module for water damage. If present, find source of water and fix. Check A-coil and/or
humidifier.
8
Status Code 4 + 2
INDUCER MOTOR FAULT - This status code indicates the inducer has not started within 20 seconds after a call for heat, the
inducer RPM is outside its valid range of operation, or the inducer RPM signal was lost for 5 seconds during operation.
STEP
ACTION
YES
NO
GO TO
1.
Shut the power off, remove both doors and disconnect communication connector PL7 (if
used) or the R thermostat lead (if used) from the furnace control board.
2
2.
Turn the power on and depress the door switch. Use a piece of tape to hold it closed.
3
3.
Jumper the R and W/W1 thermostat terminals.
4
4.
Observe the operation of the furnace for the next 8 minutes or until fault occurs.
5
5.
Does status code 4 + 2 flash?
9
6
6.
Does a different status code flash?
7
57
7.
Go to page number indicated in the Index for the section covering the status code.
INDEX
8.
Go to page number Indicated in Index for CLEANUP AND START-UP INSTRUCTIONS.
INDEX
9.
Does the inducer motor turn on?
27
10
10.
Hook an AC voltmeter across PL2-4 and L2 on the modulating furnace control. Is 115-vac
across PL2-4 and L2?
12
11
11.
Replace the modulating furnace control.
8
12.
Do you have 115-vac across PL11-2 and PL11-1?
Note:
If the furnace has an inducer motor adapter harness check for 115-vac across pin 6 and
pin 12 at the inducer motor connector. The terminals can be permanently damaged if the
voltmeter probe is jammed into the terminal end of the connector. Use caution when
checking.
14
13
13.
You have an open wire or bad terminal on either the BLACK or WHITE wire between the
modulating furnace control and the inducer motor. Repair or replace main wire harness.
8
14.
Are all pins and wire leads intact on connectors between modulating furnace control and the
inducer motor?
16
15
15.
Fix problem.
8
16.
Turn power off and disconnect jumper wire across R and W/W1 thermostat terminals.
17
17.
Turn power back on.
18
18.
Check the inducer PWM line. To do this disconnect 3-pin connector PL16 from the inducer
motor or the inducer motor adapter harness (when used), and connect a DC voltmeter across
terminals PL16-1 BROWN (+) and PL16-2 YELLOW (-).
Note:
The terminals can be permanently damaged if the voltmeter probe is jammed into the
terminal end of the connector. Use caution when checking.
Run COMPONENT TEST by turning setup switch SW1-6 ON. Does voltage across PL16-1
and PL16-2 change between states as shown below?
- State 1 – OFF (2.0 – 5.0 vdc)
- State 2 – MED (9.0 – 13.0 vdc)
23
19
19.
Turn power off.
20
20.
Do you have continuity between PL16-1 and PL1-11?
21
22
21.
Do you have continuity between PL16-2 and PL1-9?
11
22
22.
You have an open wire or bad terminal on either the BROWN or YELLOW wire between the
modulating furnace control and the inducer motor. Repair or replace the wire harness.
8
440 08 4001 00
Содержание 9MAC/E series
Страница 39: ...39 Fig 2 Wiring Schematic 440 08 4001 00...
Страница 41: ...41 Figure 3 ECM Blower Motor 440 08 4001 00...
Страница 48: ...48 Replaces New Form ICP Eng 3 12 440 08 4001 00...
