Operation CHARM: Car repair manuals for everyone.
Home >> Lincoln >> 2010 >> MKZ AWD V6-3.5L >> Repair and Diagnosis >> Steering and Suspension >> Steering >> Steering Column >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test F: DTC B2A20

Pinpoint Test F: DTC B2A20




Steering Column Switches

Pinpoint Tests

Pinpoint Test F: DTC B2A20

Refer to Wiring Diagram Set 13 (Fusion/Milan/MKZ, Fusion Hybrid/Milan Hybrid), Power Distribution/SJB for schematic and connector information. Diagrams By Number

Normal Operation

The ignition switch is spring loaded to automatically return to the RUN position after being placed in the START position. A microprocessor in the Smart Junction Box (SJB) monitors the voltage output from the ignition switch while the switch is in the START position. This microprocessor is also connected to the Audio Control Module (ACM) start circuit, so a short to voltage on the ignition switch output circuit or on the ACM start circuit could cause DTC B2A20 to set.

- B2A20 (Ignition Stuck in START) - The SJB continuously monitors the ignition switch state, if the SJB receives a START signal for more than 30 seconds, DTC B2A20 will be set.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Ignition switch
- SJB
- PCM
- ACM



PINPOINT TEST F: DTC B2A20

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.

NOTE: Verify that battery voltage is 10 volts or greater.

-------------------------------------------------
F1 CHECK THE IGNITION SWITCH MECHANICAL FUNCTION


- Inspect the ignition switch for correct mechanical function. Refer to the Ignition Switch - Mechanical Component Test. Component Tests and General Diagnostics
- Did the ignition switch pass the component test?

Yes
GO to F2.

No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F2 CHECK THE IGNITION SWITCH ELECTRICAL FUNCTION


- Ignition OFF.
- Disconnect: Ignition Switch C250.
- Carry out the Ignition Switch component test.

- Did the ignition switch pass the component test?

Yes
GO to F3.

No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F3 CHECK THE SJB START POWER OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Connect: Ignition Switch C250.
- Disconnect: SJB Fuse 28 (5A).
- Ignition ON.
- Measure the voltage between SJB fuse 28 (5A), circuit CBP28 (GY/VT), output side and ground.




- Is any voltage present?

Yes
GO to F10.

No
For non-hybrid vehicles, GO to F4.

For hybrid vehicles, GO to F9.

-------------------------------------------------
F4 CHECK THE SJB START POWER INPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Measure the voltage between SJB fuse 28 (5A), circuit CE336 (GN/WH), input side and ground.




- Is any voltage present?

Yes
GO to F5.

No
GO to F13.

-------------------------------------------------
F5 ISOLATE THE SJB START POWER CIRCUIT


- Ignition OFF.
- Disconnect: BJB One-Touch Integrated Start (OTIS) Diode.
- Ignition ON.
- Measure the voltage between SJB fuse 28 (5A), circuit CE336 (GN/WH), input side and ground.




- Is any voltage present?

Yes
GO to F6.

No
GO to F8.

-------------------------------------------------
F6 CHECK THE PCM IGNITION SWITCH INPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB C2280B.
- Ignition ON.
- Measure the voltage between SJB C2280B-32, circuit CE336 (GN/WH), harness side and ground.




- Is any voltage present?

Yes
GO to F7.

No
GO to F13.

-------------------------------------------------
F7 CHECK THE PCM FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: PCM C175B.
- Ignition ON.
- Measure the voltage between SJB C2280B-32, circuit CE336 (GN/WH), harness side and ground.




- Is any voltage present?

Yes
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.

No
GO to F15.

-------------------------------------------------
F8 CHECK THE IGNITION SWITCH START POWER OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: PCM C175B.
- Ignition ON.
- Measure the voltage between BJB OTIS diode, circuit CDC35 (BU/WH), input side and ground.




- Is any voltage present?

Yes
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.

No
GO to F15.

-------------------------------------------------
F9 CHECK THE SJB IGNITION SWITCH INPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB C2280B.
- Ignition ON.
- Measure the voltage between SJB C2280B-32, circuit CDC35 (BU/WH), harness side and ground.




- Is any voltage present?

Yes
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.

No
GO to F13.

-------------------------------------------------
F10 ISOLATE THE ACM


- Ignition OFF.
- Disconnect: ACM C240A.
- Ignition ON.
- Measure the voltage between SJB fuse 28 (5A), circuit CBP28 (GY/VT), output side and ground.




- Is any voltage present?

Yes
GO to F11.

No
GO to F14.

-------------------------------------------------
F11 ISOLATE THE PCM


- Ignition OFF.
- Disconnect: PCM C175B.
- Ignition ON.
- Measure the voltage between SJB fuse 28 (5A), circuit CBP28 (GY/VT), output side and ground.




- Is any voltage present?

Yes
GO to F12.

No
GO to F15.

-------------------------------------------------
F12 ISOLATE THE SJB


- Ignition OFF.
- Disconnect: SJB C2280B.
- Ignition ON.
- Measure the voltage between SJB C2280B-2, circuit CBP28 (GY/VT), harness side and ground.




- Is any voltage present?

Yes
REPAIR circuit CBP28 (GY/VT). CLEAR the DTCs. REPEAT the self-test.

No
GO to F13.

-------------------------------------------------
F13 CHECK FOR CORRECT SJB OPERATION


- Ignition OFF.
- Disconnect: All SJB connectors.
- Check the SJB connectors for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: All SJB connectors making sure that they are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. REFER to Body Control Systems. CLEAR the DTCs. REPEAT the self-test.

No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F14 CHECK FOR CORRECT ACM OPERATION


- Disconnect: All ACM connectors.
- Check all ACM connectors for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: All ACM connectors making sure that all connectors are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new ACM. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the self-test.

No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F15 CHECK FOR CORRECT PCM OPERATION


- Disconnect: All PCM connectors.
- Check all PCM connectors for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: All PCM connectors making sure that all connectors are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new PCM. REFER to Computers and Control Systems. CLEAR the DTCs. REPEAT the self-test.

No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
pro multis · About Operation CHARM