Pinpoint Test A : B129C:08

NOTE: Before disconnecting any of the active park assist sensors, verify the connectors are properly seated and latched.

Refer to Parking Aid for schematic and connector information.

Normal Operation and Fault Conditions

REFER to: Parking Aid - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
IPMB B129C:08	Left Front Side Sensor: Bus Signal/Message Failures	A continuous and on-demand DTC that sets in the IPMB when there is a message failure on the LIN for the left front active park assist sensor.

Possible Sources

Wiring, terminals or connectors
Left front active park assist sensor
IPMB

A1 CHECK THE DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE IPMB (IMAGE PROCESSING MODULE B) SELF-TEST

Ignition ON.

Using a diagnostic scan tool, perform the IPMB self-test.

Check the IPMB Diagnostic Trouble Codes (DTCs) from the self-test.

Are Diagnostic Trouble Codes (DTCs) for multiple front parking aid sensors recorded?

Yes

GO to A2

No	* For Diagnostic Trouble Codes (DTCs) B129C:08 GO to A3 * For all other IPMB Diagnostic Trouble Codes (DTCs), REFER to Diagnostic Trouble Code (DTC) Chart .

A2 CHECK THE FRONT BUMPER WIRING HARNESS
- Inspect the front bumper wiring harness for opens, shorts, grounds or corrosion.
Is the front bumper wiring harness OK?

Yes GO to A3

No REPAIR or INSTALL a new front bumper wiring harness.

A3 CHECK FOR VOLTAGE TO THE SENSOR

Ignition OFF.

Disconnect left front active park assist sensor C1607.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1607-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 9 volts?

Yes

GO to A4

No	REPAIR the circuit.

A4 CHECK FOR GROUND AT THE SENSOR

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1607-1	Courtesy of FORD MOTOR COMPANY	C1607-3

Is the voltage greater than 9 volts?

Yes

GO to A5

No	REPAIR the circuit.

A5 CHECK THE SENSOR FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1607-2	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to A6

No	REPAIR the circuit.

A6 CHECK THE SENSOR FOR A SHORT TO POWER

Disconnect IPMB C3676B.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1607-2	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the affected circuits.

GO to A7

A7 CHECK THE SENSOR FOR A SHORT TO VREF OR SIGNAL RETURN CIRCUITS

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1607-2	Courtesy of FORD MOTOR COMPANY	C1607-1
C1607-2	Courtesy of FORD MOTOR COMPANY	C1607-3

Are the resistances greater than 10, 000 ohms?

Yes

GO to A8

No	REPAIR the affected circuits.

A8 CHECK THE SENSOR CIRCUITS FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1607-1	Courtesy of FORD MOTOR COMPANY	C3676B-19
C1607-2	Courtesy of FORD MOTOR COMPANY	C3676B-20
C1607-3	Courtesy of FORD MOTOR COMPANY	C3676B-6

Are the resistances less than 3 ohms?

Yes

GO to A9

No	REPAIR the affected circuit.

A9 INSTALL A KNOWN GOOD SENSOR
- Connect IPMB C3676B.
- Install a known good sensor for the suspect left front active park assist sensor. REFER to: Front Active Park Assist Sensors .
- Ignition ON.
- Using a diagnostic scan tool, clear the IPMB Diagnostic Trouble Codes (DTCs) and repeat the self-test.
Is DTC B129C:08 still present?

Yes GO to A10

No INSTALL a new left front active park assist sensor. REFER to: Front Active Park Assist Sensors .

A10 CHECK FOR CORRECT IPMB (IMAGE PROCESSING MODULE B) OPERATION

Ignition OFF.

Disconnect and inspect all IPMB connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the IPMB connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new IPMB. REFER to: Image Processing Module B (IPMB) .

No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.