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.
2008 Acura TSX L4-2.4LFACTORY OEM SERVICE PROCEDURE
Control Unit Input Test
Control Unit Input Test
1. Before testing the keyless entry/security control functions, troubleshoot the multiplex integrated control system.
Multiplex Integrated Control Unit
2. Remove the left kick panel.
3. Disconnect the under-dash fuse/relay box connectors.
NOTE: All connectors are shown from the wire side of female terminals.
4. Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 5.
5. With the connectors still disconnected, make these input tests at the connectors.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If the input tests prove OK, go to step 6.
6. Reconnect all connectors to the under-dash fuse/relay box, turn the ignition switch ON (II), and make these input tests at the appropriate connectors on the under-dash fuse/relay box.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 7.
Door Multiplex Control Unit
7. Remove the driver's power window switch panel.
8. Disconnect the 23P connector from the power window master switch.
9. Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 10.
10. Reconnect the connector to the door multiplex control unit, turn the ignition switch ON (II) and make these input tests at the connectors.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 11.
11. If all the input tests prove OK, and no DTCs were found during multiplex integrated control system troubleshooting (B-CAN System Diagnosis Test Mode A), go to the B-CAN system input and output index. Description and Operation If multiple failures are found on more than one control unit, replace the under-dash fuse/relay box (includes the MICU). If input failures are related to a particular control unit, replace that control unit.
1. Before testing the keyless entry/security control functions, troubleshoot the multiplex integrated control system.
Multiplex Integrated Control Unit
2. Remove the left kick panel.
3. Disconnect the under-dash fuse/relay box connectors.
NOTE: All connectors are shown from the wire side of female terminals.
4. Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 5.
5. With the connectors still disconnected, make these input tests at the connectors.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If the input tests prove OK, go to step 6.
6. Reconnect all connectors to the under-dash fuse/relay box, turn the ignition switch ON (II), and make these input tests at the appropriate connectors on the under-dash fuse/relay box.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 7.
Door Multiplex Control Unit
7. Remove the driver's power window switch panel.
8. Disconnect the 23P connector from the power window master switch.
9. Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 10.
10. Reconnect the connector to the door multiplex control unit, turn the ignition switch ON (II) and make these input tests at the connectors.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 11.
11. If all the input tests prove OK, and no DTCs were found during multiplex integrated control system troubleshooting (B-CAN System Diagnosis Test Mode A), go to the B-CAN system input and output index. Description and Operation If multiple failures are found on more than one control unit, replace the under-dash fuse/relay box (includes the MICU). If input failures are related to a particular control unit, replace that control unit.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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