Lennox Signature XP21 Series Installation And Service Procedure page 39

Flash or Pause State
Flash Flash
Slow Flash
Short Pause
Long Pause
Unit Status
Mismatched RPM
CRC Failure
Table 16. Fan Motor Control Stage Operation LED Indicator Codes
Unit Status
Two Stage Operation
Table 17. Multi−Stage
CFM Profile Pin Select
Application
4
XP21−024 ON
XP21−036 ON
XP21−048 ON
XP21−060 ON
* LED Code indicates Fan Motor Control LED flash sequence. For example, LED Code 9 indicates 9 slow flashes and pause.
Table 14. Fan Motor Control Flash and Pause Durations
Table 15. Fan Motor Control Error/Fault LED Codes
Motor Control LED
Fast Flash with no pause
Constant ON.
Unit Status
Low Stage
High Stage
EDA Operation
Fan Motor Control RPM Jumper Settings, LED RPM Indicator and P2 DC
Low Stage
3 2 1 RPM
ON OFF ON 425
OFF ON ON 525
OFF OFF ON 600
OFF OFF OFF 625
ECM1/Y1 ONLY
ECM1/Y1 and ECM2/Y2
ECM2/Y2 ONLY
Voltage Outputs
ECM1/Y1 High Stage
Only
LED
DC
RPM
Volt
Code
6 13.6 500
7 16.8 600
8 19.2 675
8 20.0 700
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Duration
Three flashes per second
One flash per second
Two seconds of OFF time.
Five seconds of OFF time.
Possible Cause
Internal feedback, PWM does not match target.
Microcontroller CRC failure.
Motor Control LED
One slow flash, then short pause.
Two slow flash, then short pause.
Three slow flash, then short pause.
EDA Operation
ECM1/Y1
ECM2/Y2 Only
and ECM2/Y2
LED
DC
RPM
Volt
Code
7 16.0 200
8 19.2 225
9 21.6 225
10 22.5 225
LED
DC
Volt
Code
3 6.3
3 7.0
3 7.0
3 7.0
XP21