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.
DTC C1AF8: Rr IPA Sensor Communication Circuit [12/2018 -]: Procedure
- VEHICLE CONDITION AND WORK DETAILS CHECK
- Check the vehicle condition and work details.
Result
Result Proceed to The clearance warning ECU assembly or ultrasonic sensor has not been replaced A The clearance warning ECU assembly or ultrasonic sensor has been replaced B
Result:
B
GO TO CALIBRATION. Refer to CALIBRATION [12/2018 -]
Result:
A
See step 2
- Check the vehicle condition and work details.
- CHECK DTC
Result:
NEXT
See step 3
- CLEAR DTC
Result:
NEXT
See step 4
- CHECK DTC OUTPUT (C1AF8)
- Recheck for DTCs.
Body Electrical > IPA/ICS/Clearance Sonar > Trouble Codes
Result
Result Proceed to C1AF8 is not output A C1AF8 is output B
Result:
A
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2018 - 07/2020] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [07/2020 - 06/2021] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [06/2021 -]
Result:
B
See step 5
- Recheck for DTCs.
- CHECK CONNECTOR CONNECTION CONDITION (CLEARANCE WARNING ECU ASSEMBLY)
- Check that the connector is properly connected to the clearance warning ECU assembly.
Result
Proceed to NEXT
Result:
NEXT
See step 6
- Check that the connector is properly connected to the clearance warning ECU assembly.
- CLEAR DTC
Result:
NEXT
See step 7
- CHECK DTC OUTPUT (C1AF8)
- Recheck for DTCs.
Body Electrical > IPA/ICS/Clearance Sonar > Trouble Codes
Result
Result Proceed to C1AF8 is not output A C1AF8 is output B
Result:
A
END (CONNECTOR CONNECTION MALFUNCTION)
Result:
B
See step 8
- Recheck for DTCs.
- CHECK CONNECTOR CONNECTION CONDITION (ULTRASONIC SENSOR)
- Check that the connector is properly connected to the rear side ultrasonic sensor sensor.
Result
Proceed to NEXT
Result:
NEXT
See step 9
- Check that the connector is properly connected to the rear side ultrasonic sensor sensor.
- CLEAR DTC
Result:
NEXT
See step 10
- CHECK DTC OUTPUT (C1AF8)
- Recheck for DTCs.
Body Electrical > IPA/ICS/Clearance Sonar > Trouble Codes
Result
Result Proceed to C1AF8 is not output A C1AF8 is output B
Result:
A
END (CONNECTOR CONNECTION MALFUNCTION)
Result:
B
See step 11
- Recheck for DTCs.
- CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - REAR SIDE ULTRASONIC SENSOR LH)
- Disconnect the F26 clearance warning ECU assembly connector.
- Disconnect the P1 rear side ultrasonic sensor LH connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
(F26, P1)
(F26)
(P1)
Tester Connection Condition Specified Condition F26-21 (CSB2) - P1-4 (S1) Always Below 1 Ω F26-26 (LIN2) - P1-5 (S2) Always Below 1 Ω F26-25 (CSG2) - P1-6 (E2) Always Below 1 Ω F26-21 (CSB2) or P1-4 (S1) - Body ground Always 10 kΩ or higher F26-26 (LIN2) or P1-5 (S2) - Body ground Always 10 kΩ or higher F26-25 (CSG2) or P1-6 (E2) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 12
- CHECK HARNESS AND CONNECTOR (REAR SIDE ULTRASONIC SENSOR LH - REAR SIDE ULTRASONIC SENSOR RH)
- Disconnect the P2 rear side ultrasonic sensor RH connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
(P1, P2)
(P1)
(P2)
Tester Connection Condition Specified Condition P1-1 (S3) - P2-4 (S5) Always Below 1 Ω P1-2 (S4) - P2-5 (S6) Always Below 1 Ω P1-3 (E3) - P2-6 (E4) Always Below 1 Ω P1-1 (S3) or P2-4 (S5) - Body ground Always 10 kΩ or higher P1-2 (S4) or P2-5 (S6) - Body ground Always 10 kΩ or higher P1-3 (E3) or P2-6 (E4) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 13
- REPLACE REAR SIDE ULTRASONIC SENSOR LH
- Replace the rear side ultrasonic sensor LH with a known good one.
HINT:
Refer to REMOVAL [12/2018 -]
Result
Proceed to NEXT
Result:
NEXT
See step 14
- Replace the rear side ultrasonic sensor LH with a known good one.
- CLEAR DTC
Result:
NEXT
See step 15
- CHECK DTC (C1AF8)
- Check for DTCs.
Body Electrical > IPA/ICS/Clearance Sonar > Trouble Codes
Result
Result Proceed to C1AF8 is not output A C1AF8 is output B
Result:
A
END (REAR SIDE ULTRASONIC SENSOR LH WAS DEFECTIVE)
Result:
B
See step 16
- Check for DTCs.
- REPLACE REAR SIDE ULTRASONIC SENSOR RH
- Replace the rear side ultrasonic sensor RH with a known good one.
HINT:
Refer to REMOVAL [12/2018 -]
Result
Proceed to NEXT
Result:
NEXT
See step 17
- Replace the rear side ultrasonic sensor RH with a known good one.
- CLEAR DTC
Result:
NEXT
See step 18
- CHECK DTC (C1AF8)
- Check for DTCs.
Body Electrical > IPA/ICS/Clearance Sonar > Trouble Codes
Result
Result Proceed to C1AF8 is not output A C1AF8 is output B
Result:
A
END (REAR SIDE ULTRASONIC SENSOR RH WAS DEFECTIVE)
Result:
B
REPLACE CLEARANCE WARNING ECU ASSEMBLY. Refer to REMOVAL [12/2018 - 07/2020] , or refer to REMOVAL [07/2020 -]
- Check for DTCs.
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:
- • 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.