Pinpoint Test E: DTC B2A20
Steering Column Switches
Pinpoint Tests
Pinpoint Test E: B2A20
Refer to Wiring Diagram Set 13, 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.
- DTC 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
- Audio Control Module (ACM)
PINPOINT TEST E: B2A20
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
NOTE: Verify that battery voltage is 10 volts or greater.
-------------------------------------------------
E1 CHECK THE IGNITION SWITCH MECHANICAL FUNCTION
- Inspect the ignition switch for mechanical function. Refer to the Ignition Switch - Mechanical Component Test. Component Tests and General Diagnostics
- Is the ignition switch OK?
Yes
GO to E2.
No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. TEST the system for normal operation.
-------------------------------------------------
E2 CHECK THE IGNITION SWITCH FOR A SHORT
- Carry out the Ignition Switch - Electrical Component Test.
- Is the ignition switch OK?
Yes
GO to E3.
No
INSPECT the connector for corrosion, pushed-out pins or spread terminals. REPAIR as necessary. If the connector is OK, INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. TEST the system for normal operation.
-------------------------------------------------
E3 CHECK THE ACM START POWER CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB Fuse 28 (5A).
- Ignition ON.
- Measure the voltage between fuse 28 (5A), circuit CBP28 (GY/VT), output cavity and ground.
- Is any voltage present?
Yes
GO to E4.
No
GO to E5.
-------------------------------------------------
E4 ISOLATE THE ACM START POWER CIRCUIT
- Ignition OFF.
- Disconnect: ACM C240A.
- Ignition ON.
- Measure the voltage between fuse 28 (5A), circuit CBP28 (GY/VT), output cavity and ground.
- Is any voltage present?
Yes
REPAIR circuit CBP28 (GY/VT). CLEAR the DTC. REPEAT the self-test.
No
INSTALL a new ACM. REFER to Accessories and Optional Equipment. CLEAR the DTC. REPEAT the self-test.
-------------------------------------------------
E5 CHECK THE SJB START POWER CIRCUIT FOR A SHORT TO VOLTAGE
- Measure the voltage between fuse 28 (5A), circuit CDC35 (BU/WH), input cavity and ground.
- Is any voltage present?
Yes
GO to E6.
No
GO to E9.
-------------------------------------------------
E6 ISOLATE THE SJB START POWER CIRCUIT
- Disconnect: Start Diode.
- Measure the voltage between fuse 28 (5A), circuit CDC35 (BU/WH), input cavity and ground.
- Is any voltage present?
Yes
GO to E7.
No
GO to E8.
-------------------------------------------------
E7 ISOLATE THE PCM
- Ignition OFF.
- Disconnect: PCM C175B.
- Ignition ON.
- Measure the voltage between fuse 28 (5A), circuit CDC35 (BU/WH), input cavity and ground.
- Is any voltage present?
Yes
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new PCM. REFER to Computers and Control Systems. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
E8 CHECK THE IGNITION SWITCH START OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: PCM C175B.
- Ignition ON.
- Measure the voltage between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit CDC35 (BU/WH). CLEAR the DTC. REPEAT the self-test.
No
INSTALL a new PCM. REFER to Computers and Control Systems. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
E9 CHECK FOR CORRECT SJB OPERATION
- Disconnect: SJB C2280B.
- Check the SJB connector for:
- corrosion.
- pushed-out pins.
- spread terminal.
- Connect: SJB C2280B.
- Make sure the connector is seated correctly, then 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.
-------------------------------------------------