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Trane Error Code 2nd digit b: AOC jumper pin engaged (A1000AA board) (AC)

Updated · by Aurora Star Tech Inc.

Trane error code 2nd digit b on a air conditioner means: AOC jumper pin engaged (A1000AA board). It is also called Trane diagnostic code 2nd digit b.

Medium severityAir ConditionerAlso Heat PumpTrane 5TTR7

Homeowner? What Trane code 2nd digit b means for you

Check, then call Your air conditioner is reporting: AOC jumper pin engaged (A1000AA board). This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Check both breakers and the outdoor disconnect box beside the outdoor unit; all should be ON.
  • Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
  • Keep about 2 feet around the outdoor unit clear of leaves, grass and debris.
  • If you see ice on the pipes or the indoor coil, turn the system off and run only the fan for a few hours, then call a technician.
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Trane error code 2nd digit b mean?

On A1000AA boards the right-hand 7-segment digit shows the fault and the left digit shows status; this value means: aoc jumper pin engaged. Manual gives only the meaning; steps are general checks.

Applies to: Trane 5TTR7 multi-speed AC (5TTR7024A-060A) with A1000AA control

Common causes of Trane code 2nd digit b

  • Service jumper left on the board
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Trane models that use code 2nd digit b

5TTR7024A5TTR7036A5TTR7048A5TTR7060A

Other Trane AC codes

CodeMeaning
2nd digit 5Outdoor fan over-current protection (A1000AA board)
2nd digit 6High preheat IPM temperature (A1000AA board)
2nd digit 7High coil temperature protection (A1000AA board)
2nd digit 8High discharge temperature protection (A1000AA board)
2nd digit 9High drive compressor IPM temperature (A1000AA board)
2nd digit AOutdoor ambient sensor fault (A1000AA board)
2nd digit CCoil temperature sensor fault (A1000AA board)
2nd digit dDischarge temperature sensor fault (A1000AA board)
2nd digit EHigh drive PFC temperature protection (A1000AA board)
2nd digit FHigh drive fan IPM temperature protection (A1000AA board)
2nd digit PPressure protection (high or low) (A1000AA board)
d5De-rate: drive AC input over-current

All Trane Air Conditioner error codes →

Trane code 2nd digit b: homeowner questions

What does Trane code 2nd digit b mean?

AOC jumper pin engaged (A1000AA board). On A1000AA boards the right-hand 7-segment digit shows the fault and the left digit shows status; this value means: aoc jumper pin engaged. Manual gives only the meaning; steps are general checks.

Is it safe to keep using my air conditioner with code 2nd digit b?

It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Can I reset Trane code 2nd digit b myself?

You can try one reset (power off for 30 seconds, then on). If Trane code 2nd digit b comes back, the cause is still there and a licensed technician should check it.

Who can fix Trane code 2nd digit b near me?

Aurora Star Tech Inc. repairs Trane air conditioners in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: AC Running But Not Cooling: What to Check

Troubleshooting guides

Source: Trane ODR-SVN002E-EN (5TTR7/5TWR7 installer's guide) - section Integrated Variable Speed Control Board LED Indicators, Table 17 (A1000AA models). Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency HVAC Service

647-657-2977