Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
A/C Signal Circuit Troubleshooting (Idle Control System)
2011 Acura TSX Sport Wagon L4-2.4LSECTION A/C Signal Circuit Troubleshooting (Idle Control System)
A/C Signal Circuit Troubleshooting
1. Start the engine, and let it idle.
2. Turn the blower switch on.
3. Turn the A/C switch on.
4. Check the A/C CLUTCH in the DATA LIST with the HDS.
Does it indicate ON?
YES -
Go to step 5.
NO -
Do the A/C system test A/C System Inspection.οΏ½
5. Check the A/C system.
Does the A/C system operate?
YES -
The air conditioning system circuit is OK.οΏ½
NO -
Go to step 6.
6. Turn the ignition switch to LOCK (0).
7. Turn the ignition switch to ON (II).
8. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS.
Is there a clicking noise from the A/C compressor clutch?
YES -
Do the A/C system test A/C System Inspection.οΏ½
NO -
Go to step 9.
9. Turn the ignition switch to LOCK (0).
10. Jump the SCS line with the HDS.
11. Disconnect ECM/PCM connector A (49P).
12. Turn the ignition switch to ON (II).
13. Momentarily connect ECM/PCM connector terminal A15 to body ground with a jumper wire several times.
Is there a clicking noise from the A/C compressor clutch?
YES -
Reconnect all connectors, and update the ECM/PCM if it does not have the latest software ECM/PCM Update (M/T), or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away and the ECM/PCM was updated, troubleshooting is complete. If the symptom/indication goes away, and the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.οΏ½
NO -
Check for poor connections or loose terminals at the A/C compressor clutch relay and the ECM/PCM. If the connections are OK, check the A/C compressor clutch relay Testing and Inspection. If needed, repair open in the wire between the ECM/PCM (A15) and the A/C compressor clutch relay, and check the other parts in the A/C systems.οΏ½
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.