Visual Inspection and Diagnostic Pre-checks

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Make sure the aspirator valve housing is not cracked, missing pieces or damaged.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

CC1: CHECK THE POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODES (DTCS)

Ignition ON.
Using a diagnostic scan tool, carry out the PCM module self-test.

Are any PCM Diagnostic Trouble Codes (DTCs) present?

Yes	No
Go to CC2.	For DTC P103E, Go to CC4. For DTC P103C, Go to CC5. For all others PCM Diagnostic Trouble Codes (DTCs), REFER to the appropriate Electronic Engine Controls article.

CC2: CHECK FOR VOLTAGE TO THE ASPIRATOR VALVE

Ignition OFF.
Disconnect Vacuum Solenoid Valve C1795 .
Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1795 Pin 2		Ground Pin -

Is the voltage greater than 11 V?

Yes	No
Go to CC3.	REPAIR the circuit.

CC3: CHECK THE ASPIRATOR VALVE CONTROL CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.
Disconnect PCM B connector.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1795 Pin 1	Ω	Ground Pin -

Is the resistance greater than 10,000 ohms?

Yes	No
Go to CC4.	VERIFY BJB fuse 26 (15A) is OK. If the fuse is OK, REPAIR the circuit. If the fuseis not OK, REFER to the appropriate Wiring Diagrams article to identify the cause of the circuit short.

CC4: CHECK THE ASPIRATOR VALVE CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1795 Pin 1		Ground Pin -

Is the voltage greater than 0 volts?

Yes	No
REPAIR the circuit.	Go to CC5

CC5: CHECK THE ASPIRATOR VALVE CONTROL CIRCUIT FOR AN OPEN

Ignition OFF.

Yes	No
Go to CC6.	REPAIR the circuit.

CC6: VERIFY ALL WIRING CONNECTIONS

Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary

Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?

Yes	No
Go to CC7.	REPAIR the connector or terminals. REFER to CONNECTOR REPAIR PROCEDURES for schematic and connector information.

CC7: VERIFY SYSTEM OPERATION

Connect Vacuum Solenoid Valve C1795 . Make sure the connector seats and latches correctly.
Connect PCM B connector. Make sure the connector seats and latches correctly.
Ignition ON.
Using a diagnostic scan tool, clear the PCM module DTCs .
Start the engine.
Press the brake pedal as many times as necessary to exhaust the vacuum in the brake booster.
Allow the brake booster vacuum to recharge.
Ignition OFF.
Ignition ON.
Using a diagnostic scan tool, carry out the PCM module self-test.
Retrieve and record the PCM DTCs .

Is DTC P103C, P103D or P103E still present?

Yes	No
CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new vacuum hose and aspirator valve assembly.	The system is operating correctly at this time. The concern may have been caused bya loose or corroded connector. ADDRESS the root cause of any connector or pinissues. REFER to CONNECTOR REPAIR PROCEDURES for schematic and connector information.