The BCM receives three voltage inputs. The BCM receives voltage from the (10A fuse that is in cavities A7 and A8 of the fuse block) circuit at all times except when the ignition switch is off. The BCM receives voltage from the (10A fuse that is in cavities D9 and D10 of the fuse block) circuit when the ignition switch is in the ON or START position. The BCM receives voltage from the (10A fuse that is in cavities A3 and A4 of the fuse block) crank circuit when the ignition switch is in the start position.
The BCM sets DTC B0608 when detecting any of these conditions for more than 0.3 seconds:
• | Voltage in IGN 1 circuit is greater than 8 volts, and voltage in the IGN 0 circuit is less than 1.5 volts. |
• | Voltage in the crank circuit is greater than 4.5 volts, and the voltage in the IGN 0 circuit is less than 1.5 volts. |
• | Voltage in the crank circuit is greater than 4.5 volts, and the voltage in the IGN 1 circuit is less than 1.5 volts. |
the BCM stores DTC B0608 in memory.
• | The BCM no longer detects an open or short to B+ in the IGN 1circuit, the IGN 0 circuit, or the CRANK circuit. |
• | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
• | Using a scan tool. |
• | If the DTC B0608 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
• | The following conditions may cause an intermittent malfunction to occur: |
• | An intermittent open or short to B+ in the IGN 1 circuit, the IGN 0 circuit, or the CRANK circuit. |
• | Poor connections at the BCM, or the fuse block. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for a short to ground in the crank circuit.
This step tests for a short to ground in the IGN 0 circuit.
This step tests for a short to B+ in the IGN 0 circuit.
This step tests for an open in the IGN 1 circuit.
This step tests for a short to B+ in the crank circuit.
This step tests for an open in the crank circuit.
This step tests for a short to B+ in the IGN 0 circuit.
This test tests for an open in the IGN 0 circuit.
This test determines whether the malfunction is intermittent or whether the BCM is faulty.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Was the BCM Diagnostic System Check performed? | -- | ||
Check the 10A fuse in cavities A3 and A4 of the fuse block. Is the 10A fuse in cavities A3 and A4 of the fuse block open? | -- | |||
3 |
IMPORTANT: The engine may start. Is the 10A fuse in cavities A3 and A4 of the fuse block open again? | -- | ||
Check the 10A fuse in cavities A7 and A8 of the fuse block. Is the 10A fuse in cavities A7 and A8 of the fuse block open? | -- | |||
5 |
Is the 10A fuse in cavities A7 and A8 of the fuse block open again? | -- | ||
Does the test light stay off? | -- | |||
7 |
Important: The engine may start. Was the test light on with the ignition switch in the RUN and START position? | -- | ||
Did the test lamp stay off when turning the ignition switch from the OFF position to the RUN position? | -- | |||
Important: The engine may start. Did the test lamp turn on when turning the ignition switch to the START position? | -- | |||
Does the test lamp stay off? | -- | |||
Important: The engine may start. Did the test light turn on with the ignition switch in the ACC, RUN or START position? | -- | |||
Does DTC B0608 reset as a current DTC? | -- | |||
13 | Repair short to ground in the crank circuit. Is the repair complete? | -- | -- | |
14 | Repair short to ground in the IGN 0 circuit. Is the repair complete? | -- | -- | |
15 | Repair short to voltage in the IGN 1 circuit. Is the repair complete? | -- | -- | |
16 | Repair poor connection or open in the IGN 1 circuit. Is the repair complete | -- | -- | |
17 | Repair short to voltage in the crank circuit or a faulty ignition switch. Is the repair complete? | -- | -- | |
18 | Repair poor connection or open in the crank circuit. Is the repair complete? | -- | -- | |
19 | Repair short to voltage in the IGN 0 circuit or a faulty ignition switch. Is the repair complete? | -- | -- | |
20 | Repair poor connection or open in the IGN 0 circuit. Is the repair complete? | -- | -- | |
21 |
Is the repair complete? | -- | -- | |
22 | The malfunction is not present at this time. Refer to Diagnostic Aids for additional information regarding this DTC. Is the action complete? | -- | -- | |
23 |
Are there any current BCM DTCs set? | -- | System OK |