Carrier 58SU0A - Status Code 25 - Setup Error; Status Code 26 - Wiring Harness

58SU0A (Series 2 & 3): Troubleshooting Guide
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Status Code 25 - Setup Error
Indicates model plug PL4 is missing or incorrect.
Status Code 26 - Wiring Harness
Indicates yellow jumper in main plug of harness is damaged or missing
A230410
Fig. 1 – Wiring Harness
STEP ACTION YES NO GO TO
1.
Turn power off, remove blower the blower access panel, and disconnect the R thermostat lead from
the furnace control board.
2
2. Turn power on and depress door switch. Use a piece of tape to hold switch closed. 3
3. Does status code 25 flash only 4 times on power-up? 4 7
4.
The model plug is missing or invalid, but the control will default to the model stored in memory. The
furnace will operate properly as if the model plug was installed.
5
5. Install correct model plug 6
6. Go to page number indicated in Index for CLEANUP AND START- UP INSTRUCTIONS. INDEX
7. Is this a new service replacement control? 8 10
8.
You need to remove the model plug PL4 from the old control and install it on the new replacement
control. Once you install the model plug the power to the furnace needs to be cycled because the
model plug is only read on power-up.
9
9.
If the model plug is not available from the old control, reference the model plug chart on the rating
plate for the correct part number. If necessary, you can install two resistors into the PL4 connection
on the control board. R1 goes across the middle 2 pins and R2 goes across the outer 2 pins. The
resistors need to be within 10% of the required value. Check with an ohm meter before installing.
6
10.
Turn power off and remove model plug from PL4. Measure model plug resistance and compare with
values noted on rating plate. Are values within 10% of expected?
11 12
11. Replace the furnace control. 6
12. One of the model plugs resistors is bad. Replace the model plug 6
STEP ACTION YES NO GO TO
1. Turn power off, remove the blower access panel. 2
2. Disconnect PL1 from furnace control. 3
3. Do you have continuity on the yellow jumper wire between PL1-2 and PL1-4? 5 4
4. Repair or replace harness 6
5. Replace furnace control 6
6. Go to page number indicated in Index for CLEANUP AND START-UP INSTRUCTIONS. INDEX