DTC B1826: Power Seat Front Up-down Motor Pulse Error Acura RL II facelift

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ). DTC B1826 is stored when the front up-down switch is operated more than 1 second after the seat moves to the most up or most down position, even when the system is OK.

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 42

Scheme 43

1. Clear the DTCs with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Operate the power seat adjustment switch in each direction for at least 1 second each.
4. Check for the DTCs with the HDS. Is DTC B1826 indicated? YES -Go to step 5. NO -Intermittent failure, the front up-down position sensor is OK at this time. Check for loose or poor connections at the power seat control unit connectors.
5. Check for DTCs with the HDS. Is DTC B1836 also indicated? YES -Troubleshoot DTC B1836 first (see «DTC B1836: POWER SEAT POSITION SENSOR CIRCUIT SHORT»(ref-348587-S03678842062009112400000) ). NO -Go to step 6.
6. Check for DTCs with the HDS. Are DTCs B1825, B1827 and/or B1828 also indicated? YES -Go to step 18 . NO -Go to step 7.
7. Clear the DTCs with the HDS.
8. Turn the ignition switch to LOCK (0), and then back to ON (II).
9. Operate the front up-down switch for at least 2 seconds, and check the front up-down motor operation. Does the front up-down motor run smoothly? YES -Go to step 10. NO -Go to step 25 .
10. Turn the ignition switch to LOCK (0).
11. Disconnect power seat control unit connector A (40P).
12. Disconnect the front up-down motor/position sensor 5P connector.
13. Check for continuity between power seat control unit connector A (40P) terminals No. 12, No. 15, and No. 29 and front up-down motor/position sensor 5P connector terminals No. 3, No. 4, and No. 5 respectively. Is there continuity? YES -Go to step 14. NO -Repair open in the wire.
14. Check for continuity between power seat control unit connector A (40P) terminal No. 12 and body ground. Is there continuity? YES -Repair short to ground in the wire. NO -Go to step 15.
15. Reconnect power seat control unit connector A (40P).
16. Turn the ignition switch to ON (II).
17. Measure the voltage between front up-down motor/position sensor 5P connector terminals No. and No. 5. Is there about 5 V? YES -Replace the front up-down motor/position sensor. NO -If there is no voltage, replace the power seat control unit. If there is battery voltage, repair short in the wire (sensor line).
18. Turn the ignition switch to LOCK (0).
19. Disconnect power seat control unit connector A (40P>.
20. Disconnect the front up-down motor/position sensor 5P connector.
21. Check for continuity between power seat control unit connector A (40P) terminals No. 15 and No. 29 and front up-down motor/position sensor 5P connector terminals No. 3 and No. 4 respectively. Is there continuity? YES -Go to step 22. NO -Repair open in the wire.
22. Reconnect power seat control unit connector A (40P).
23. Turn the ignition switch to ON (II).
24. Measure the voltage between power seat control unit connector A (40P) terminals No. 15 and No. 29. Is there battery voltage when the front up-down switch is operated? YES -Replace the front up-down motor/position sensor, and recheck for DTCs. NO -Replace the power seat control unit.
25. Turn the ignition switch to LOCK (0).
26. Disconnect power seat control unit connector B (18P).
27. Disconnect the front up-down motor/position sensor 5P connector.
28. Check for continuity between power seat control unit connector B (18P) terminals No. 6 and No. 16 and front up-down motor/position sensor 5P connector terminals No. 1 and No. 2 respectively. Is there continuity? YES -Go to step 29. NO -Repair open in the wire.
29. Check for continuity between front up-down motor/ position sensor 5P connector terminals No. 1 and No. 2 and body ground. Is there continuity? YES -Repair short to ground in the wire. NO -Go to step 30.
30. Do the front up-down motor test (see «DRIVER'S POWER SEAT MOTOR TEST»(ref-348587-S38634851942009112400000) ). Is the motor OK? YES -Replace the power seat control unit. NO -Replace the front-up-down motor/position sensor.