FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Mercury >> 2009 >> Sable AWD V6-3.5L >> Repair and Diagnosis >> Steering and Suspension >> Steering >> Steering Column >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test F: DTCs B2844 and U2472 - Ignition Fault And Unexpected Ignition State

Pinpoint Test F: DTCs B2844 and U2472 - Ignition Fault And Unexpected Ignition State




Steering Column Switches

Pinpoint Tests


Pinpoint Test F: DTCs B2844 and U2472 - Ignition Fault and Unexpected Ignition State

Refer to Wiring Diagram Set 13, Power Distribution/SJB for schematic and connector information. Diagrams By Number

Normal Operation

The Battery Junction Box (BJB) receives battery voltage along circuit SDC02 (RD) and distributes this voltage to various fuses. The ignition switch receives fused battery voltage from BJB fuse 33 (20A) along circuit SBB33 (RD). The ignition switch then sends that voltage out to various systems depending on ignition switch position. The ignition switch has 4 possible states:

- OFF - Power on circuit CDC30 (BU/GY) to the Smart Junction Box (SJB)
- ACC - Power on circuit CDC33 (VT/GN) to the SJB
- RUN - Power on circuit CDC34 (WH/OG) to the SJB and BJB
- START - Power on circuit CDC35 (BU/WH) to the PCM and the One-Touch Integrated Start (OTIS) diode in the BJB. From the OTIS diode, the voltage is sent to the SJB, the PCM and the starter relay in the BJB along circuit CE336 (GN/WH).

The SJB continually monitors the ignition switch position and will set DTCs when certain conditions exist.

- B2844 Ignition Fault - If the SJB receives an invalid ignition switch state or cannot detect the ignition switch state during normal operation, DTC B2844 is set.
- U2472 Unexpected Ignition State - If during the SJB on-demand self test, the SJB does not receive the ignition RUN signal or any ignition switch signal, DTC U2472 is set.

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



PINPOINT TEST F: DTCs B2844 AND U2472 - IGNITION FAULT AND UNEXPECTED IGNITION STATE

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

-------------------------------------------------
F1 CHECK THE IGNITION SWITCH


- Ignition OFF.
- Carry out the Ignition Switch - Electrical Component Test.

- Is the ignition switch OK?

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 CIRCUIT CDC33 (VT/GN) FOR AN OPEN


- Ignition OFF.
- Disconnect: SJB C2280a.
- Disconnect: Ignition Switch C250.
- Measure the resistance between ignition switch C250-6, circuit CDC33 (VT/GN), harness side and SJB C2280a-3, circuit CDC33 (VT/GN), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to F3.

No
REPAIR circuit CDC33 (VT/GN). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F3 CHECK CIRCUIT CDC33 (VT/GN) FOR A SHORT TO GROUND


- Measure the resistance between ignition switch C250-6, circuit CDC33 (VT/GN), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to F4.

No
REPAIR circuit CDC33 (VT/GN). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F4 CHECK CIRCUIT CDC34 (WH/OG) FOR AN OPEN


- Disconnect: SJB C2280b.
- Disconnect: SJB C2280e.
- Disconnect: BJB Fuse 38 (10A).
- Disconnect: BJB Fuse 39 (10A).
- Measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and SJB C2280b-45, circuit CDC34 (WH/OG), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to F5.

No
REPAIR circuit CDC34 (WH/OG). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F5 CHECK CIRCUIT CDC34 (WH/OG) FOR A SHORT TO GROUND


- Measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to F6.

No
REPAIR circuit CDC34 (WH/OG). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F6 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN


- Disconnect: OTIS Diode.
- Disconnect: PCM C175b.
- Measure the resistance between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and:
- the OTIS diode, circuit CDC35 (BU/WH), input side.
- PCM C175b-9, circuit CDC35 (BU/WH), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to F7.

No
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F7 CHECK CIRCUIT CDC35 (BU/WH) FOR A SHORT TO GROUND


- Measure the resistance between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and ground.




- Is the resistance greater then 10,000 ohms?

Yes
GO to F8.

No
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F8 CHECK CIRCUIT CE336 (GN/WH) FOR AN OPEN


- Measure the resistance between OTIS diode, circuit CE336 (GN/WH), output side and:
- SJB C2280b-32, circuit CE336 (GN/WH), harness side.
- PCM C175b-35, circuit CE336 (GN/WH), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to F9.

No
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F9 CHECK CIRCUIT CE336 (GN/WH) FOR A SHORT TO GROUND


- Measure the resistance between OTIS diode, circuit CE336 (GN/WH), output side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to F10.

No
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
F10 CHECK CIRCUIT CDC33 (VT/GN) FOR A SHORT TO VOLTAGE


- Connect: SJB C2280a.
- Connect: SJB C2280b.
- Connect: SJB C2280e.
- Connect: Ignition Switch C250.
- Disconnect: SJB Fuse 45 (5A).
- Ignition ON.
- Measure the voltage between SJB fuse 45 (5A) input side, circuit CDC33 (VT/GN) and ground.




- Is any voltage present?

Yes
REPAIR circuit CDC33 (VT/GN). CLEAR the DTCs. REPEAT the self-test.

No
GO to F11.

-------------------------------------------------
F11 CHECK CIRCUIT CDC34 (WH/OG) FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB Fuse 37 (10A).
- Ignition ON.
- Measure the voltage between SJB fuse 37 (10A) input side, circuit CDC34 (WH/OG) and ground.




- Is any voltage present?

Yes
REPAIR circuit CDC34 (WH/OG). CLEAR the DTCs. REPEAT the self-test.

No
GO to F12.

-------------------------------------------------
F12 CHECK CIRCUIT CDC35 (BU/WH) FOR A SHORT TO VOLTAGE


- Measure the voltage between OTIS diode input side, circuit CDC35 (BU/WH) and ground.




- Is any voltage present?

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

No
GO to F13.

-------------------------------------------------
F13 CHECK CIRCUIT CE336 (GN/WH) FOR A SHORT TO VOLTAGE


- Measure the voltage between OTIS diode output side, circuit CE336 (GN/WH) and ground.




- Is any voltage present?

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

No
GO to F14.

-------------------------------------------------
F14 CHECK THE SJB CONNECTORS


- Disconnect: SJB C2280a.
- Disconnect: SJB C2280b.
- Disconnect: SJB C2280e.
- Check the connectors for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: SJB C2280a.
- Connect: SJB C2280b.
- Connect: SJB C2280e.
- Make sure the connectors are seated correctly, then operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. 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.

-------------------------------------------------
pro multis Credits:Operation CHARM About Operation CHARM