AWD Light Comes On and Sets DTC C1858-73 – 2013-2014 Acura RDX

B15-012
May 6, 2015
01425-01942 Version 2

AWD Light Comes On and Sets DTC C1858-73

 

AFFECTED VEHICLES

Year	Model	Trim	VIN range
2013–14	RDX	ALL with AWD	ALL with AWD

 

REVISION SUMMARY

Under PARTS INFORMATION, the AWD Fluid part number was changed.

 

SYMPTOM

The electric differential pressure solenoid (EDPS) has excessive oil pressure, causing the AWD indicator to come on and DTC C-1858-73 (differential fluid pressure deviation high) to set.

 

POSSIBLE CAUSES

There is abnormal wear on the EPDS solenoid plunger.

 

CORRECTIVE ACTION

Replace the EDPS solenoid in the rear differential.

 

PARTS INFORMATION

Part Name	Part Number	Quantity
Solenoid Assembly	48350-R7L-013	1
Bolt (12 point 8 mm x 21 mm)	90113-S10-000	4
Flange Bolt (10 mm x 31 mm)	90164-S3V-A00	4
Flange Bolt (8 mm x 14 mm)	95701-08014-08  Honda 90127-SM4-951 Bolt, Flange (8X14); New # 95701-08014-08 Made by Honda Genuine Honda part that fits your specific vehicle Flange Bolt Part Number: 90127-SM4-951 Manufactured to meet specifications for fit, form, and function $10.91 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API	2
Drain Washer (20 mm)	94109-20000  Honda Genuine OEM Rear Differential Drain/Fill Plug Washers (20mm), Bag of 10-94109-20000 Factory replacement large size crush washers, 10 pack Fits all 4WD CR-V, Element, and Crosstour drain and fill plugs Fits Ridgeline and Pilot rear differential fill plugs, and transfer case drain and fill plugs Fits all Honda manual transmission fill plugs $17.67 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API	1
Drain Washer (18 mm)	90471-PX4-000  Honda Genuine OEM Automatic Transmission Drain Plug Washers (18mm), Bag of 5-90471-PX4-000 Factory replacement automatic transmission drain plug washers, 5 pack Fits all Honda automatic transmission drain plugs Fits all Pilot and Ridgeline rear differential drain plugs $16.00 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API	1
O-ring (7.7 mm x 2.3 mm)	91301-PC9-003  Honda Genuine O-Ring (7-7X2-3) Genuine OEM part $9.29 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API	1
O-ring (28.4 mm x 2.4 mm)	91306-R7L-003	1
Clip	91540-STK-003  Honda 91540-STK-003 Clip (155.3MM) Honda 91540-STK-003 Clip (155.3MM) $16.42 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API	1
Liquid Gasket	08718-0004  Honda 08717-0004 Hondabond 4; New # 08717-1194 Made by Honda New $11.90 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API	1
AWD Fluid	08200-9007A  No products found.	2

 

WARRANTY CLAIM INFORMATION

The normal warranty applies.

Operation Number	Description	Flat Rate Time	Failed Part Number
2191Y0	Replace the EPDS solenoid.	1.4 hours	48350-R7L-003

Defect Code: 03217
Symptom Code: 03214
Skill Level: Repair Technician

 

REPAIR PROCEDURE

1. Raise the vehicle on a lift and make sure it is securely supported.
2. Shift into Neutral.
3. Remove the oil filler plug and sealing washer from the rear differential.

 

4. Remove the drain plug and sealing washer, then drain the rear differential fluid.

 

5. Remove the No. 1 propeller shaft protector.

 

6. Disconnect the propeller shaft from the rear differential:
   • Make a reference mark across the No. 2 propeller shaft and the transfer companion flange.
   • Remove the propeller shaft flange bolts.
   • Separate the propeller shaft from the rear differential.
   • Tie off the propeller shaft with an appropriate size nylon strap.

 

7. Support the rear differential with a jack. Remove the mounting bolts and lower the differential about 1 inch.

 

8. Disconnect the breather hose from the pump motor breather pipe, then remove the harness bracket.

 

9. Disconnect the connector.

 

10. Remove the rear differential pump motor and the O-ring.

 

11. Remove the connector cover.

 

12. Disconnect the EPDS connector, then remove the solenoid connector.

 

13. Remove the bolts, then remove the torque control differential assembly.

 

14. Remove the three shims from the pump housing assembly and note the order from which they were removed.

NOTE: Make sure the large 101.5 mm shim fits into the tabs on reassembly. If the shims are removed or fall out while doing the repair, note the orientation of the shims and reinstall in the order shown.

 

15. Remove the four bolts from the pump housing assembly to remove it.

 

16. Remove the EPDS solenoid.

NOTE: If Service Bulletin 14-047, Noise From the Rear Differential, was done, make sure the intermediate drive joint does not fall out when handling the pump housing.

 

17. Install the new EPDS solenoid and torque the bolts to 12 N·m (9 lb-ft).
18. Replace the O-ring with a new one.

 

19. Install the pump housing assembly and torque the bolts to 12 N·m (9 lb-ft).
20. Install the shims in the order of removal and make sure the tabs are in place.
21. Remove the old gasket and any dirt and oil from the mating surface.
22. Apply liquid gasket evenly to the entire sealing surface and install the component within 5 minutes of applying it.

NOTE: Allow the liquid gasket to cure for 30 minutes after assembly before filling the differential with the recommended fluid.

23. Install the torque control differential assembly and torque the bolts to 12 N·m (9 lb-ft).
24. Install the solenoid connector and the EPDS connector.
25. Install the connector cover.
26. Install the rear differential pump motor with a new O-ring and torque the bolts to 12 N·m (9 lb-ft).
27. Connect the connector.
28. Install the harness bracket and the breather hose to the pipe.
29. Install the new mounting bolts and torque them to 44 N·m (32 lb-ft).
30. Install the propeller shaft:
    • Attach the propeller shaft to the rear differential companion flange by aligning the reference mark you made in step 6.
    • Install the new bolts and torque them to 32 N·m (24 lb-ft).
31. Install the propeller shaft protector and torque the bolts to 22 N·m (16 lb-ft).
32. Clean the drain plug, and install it with a new sealing washer, then torque it to 47 N·m (35 lb-ft).
33. Refill the differential to the proper level.
34. Install the oil filler plug with a new sealing washer and torque the plug to 47 N·m 35 lb-ft).
35. Connect the HDS to the DLC.
36. Turn the ignition to ON.
37. Make sure the HDS communicates with the vehicle. If it does not communicate, go to the DLC circuit troubleshooting.
38. Select REAL TIME AWD SYSTEM, ADJUSTMENT, and AIR BLEEDING.

NOTE: See the HDS Help menu for specific instructions.

END

 

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Last update on 2026-06-19 / Affiliate links / Images from Amazon Product Advertising API

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