Service Bulletin

21-055

June 11, 2021

Version 1

2017–19 Ridgeline: Alarm Goes Off Intermittently
AFFECTED VEHICLES
Year

Model

Trim

VIN Range

2017–19

Ridgeline

ALL

ALL

SYMPTOM
The vehicle’s factory security system will sound off intermittently when the vehicle is parked, and the system is armed.
POSSIBLE CAUSE
An internal failure within the Keyless Access/TPMS Control Unit.
CORRECTIVE ACTION
Inspect the Alarm Trigger History with i-HDS and replace the Keyless Access/TPMS Control Unit if Ignition Switch (IG1) is
listed under the Alarm Device.
PARTS INFORMATION
Part Name

Trim

Part Number

Quantity

Control Unit

RT (2WD and AWD)

38320-T6Z-A11

1

Control Unit

RLT, RTS, and SPORT (2WD and AWD)

38320-T6Z-A21

1

Control Unit

BLACK RTL (-E), and RTL (T 2WD and
AWD-NAV/SUN), RTL (T 2WD and AWD NAVI)

38320-T6Z-A31

1

CUSTOMER INFORMATION: The information in this bulletin is intended for use only by skilled technicians who have the proper tools, equipment,
and training to correctly and safely maintain your vehicle. These procedures should not be attempted by “do-it-yourselfers,” and you should not
assume this bulletin applies to your vehicle, or that your vehicle has the condition described. To determine whether this information applies, contact
an authorized Honda automobile dealer.

© 2021 American Honda Motor Co., Inc. – All Rights Reserved

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WARRANTY CLAIM INFORMATION
The normal warranty applies.
Operation
Number
0505A0

A

Description

Flat Rate
Time

Inspect the Security
System with the i-HDS.

0.3 hr.

RT 2WD/AWD Replace the Keyless
Access/TPMS control
unit (includes reprograming all keys and
TPMS sensor learn/tire
check).

0.8 hr.

RTL 2WD/AWD, RTS
2WD/AWD, Sport
2WD/AWD - Replace
the Keyless
Access/TPMS control
unit (includes reprograming all keys and
TPMS sensor learn/tire
check).

0.8 hr.

BLACK RTL (-E), RTL
(T 2WD/AWDNAV/SUN), RTL (T
2WD/AWD - NAVI) Replace the Keyless
Access/TPMS control
unit (includes reprograming all keys and
TPMS sensor learn/tire
check).

0.8 hr.

Defect
Code

Symptom
Code

Template
ID

Failed Part Number

A21055A

03124

03217

A21055B

38320-T6Z-A11

A21055C

Skill Level: Repair Technician

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INSPECTION PROCEDURE
1. Connect to the vehicle using the i-HDS.

2. Go to the Body Electrical menu and select Security.

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3. Select History Data.

4. If under the Alarm Device column, you see that Ignition Switch (IG1) is listed, proceed to the repair procedure. If is
not listed, this bulletin does not apply, proceed with normal troubleshooting.

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REPAIR PROCEDURE
NOTE: Before beginning work, all of the vehicle’s keys will need to be available to complete the Keyless Access
Control
Unit Registration.
1. Remove the passenger’s side dashboard lid.

2. Remove the passenger's dashboard undercover, then disconnect the connector (for some models).

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3. Remove the passenger's dashboard trim panel.

4. Open the glove box. Release both glove box stops by pushing them in passed the guide stop, then pull down the glove
box.

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5. Remove the screws.
NOTE: If the screw threads are stripped, replace them with one-size larger (90140-TG7-A00).

6. Remove the glove box, then remove the glove box light and the connector.

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7. Release the retaining clip, then remove the Keyless Access/TPMS control unit from the bracket and disconnect the
connectors.

8. Install the replacement Keyless Access/TPMS Control Unit.
9. Install all remaining parts in the reverse order of removal.

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10. Register the Keyless Access/TPMS control unit using the i-HDS Immobilizer Setup Tool. Follow the instructions when
prompted by i-HDS.
NOTE:
•
•

Make sure the 12-volt battery is fully charged before starting registration.
Connect a fully charged jumper battery to the vehicle, and leave it connected during the entire procedure to
maintain steady voltage.

11. Click through to show all the Registration Menu options. Select Replace PCU/BACK UP CONTROLLER/KEYLESS
ACCESS Control Unit. Follow the instructions when prompted by i-HDS.

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12. After registration, verify all remote related systems work normally with all remotes.
13. Perform the Tire Pressure Sensor ID with i-HDS by following the screen prompts.

14. Select Sensor ID Learning, then follow the instructions when prompted by i-HDS.
NOTE: After the sensor IDs are memorized, reduce the pressure in all four tires to less than the appropriate
specification, and check to see that the four tire indicators come on. Clear any DTCs that may have stored while
performing this check.

END
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