Table 1: | Correct Ignition Switch Inputs |
The body control module (BCM) monitors the ignition inputs Ignition Off/Run/Crank, Ignition 1 Run/Crank and the Ignition Accessory signals supplied from the ignition switch. The BCM uses the sequence that the signals appear, their voltage levels and the engine run flag (ERF) status to determine the power mode. Battery voltage is supplied to the ignition switch by a fuse in the underhood fuse block. The Ignition Accessory signal also wakes up the powertrain control module (PCM). The following table shows the correct ignition switch signals:
Ignition Switch Position | BCM Input and Scan Tool Display | ||
---|---|---|---|
Ignition Accessory | Ignition 1 Run/Crank | Ignition Off/Run/Crank | |
OFF | Inactive | Inactive | Active |
ACC | Active | Inactive | Inactive |
ON | Active | Active | Active |
START | Inactive | Active | Active |
This diagnostic procedure supports the following DTCs:
• | DTC B1382 Device Ignition Accessory ON and ACC Circuit Low |
• | DTC B1383 Device Ignition Accessory ON and ACC Circuit High |
Battery voltage is 9-16 volts.
The BCM detects that the accessory voltage circuit is open or short to ground for at least 1 second.
The BCM detects that the accessory voltage circuit is shorted to voltage for at least 10 seconds.
• | The BCM stores DTC B1382 or B1383 in memory. |
• | The BCM determines a fail-safe power mode dependent on the last valid power mode detected and the state of the ERF. |
• | A current DTC clears when the malfunction is no longer present. |
• | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction. |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Body Control System Schematics and Power Distribution Schematics Connector End View Reference: Data Communication Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the Ignition Accessory parameter display correctly? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate for either test? | Go to Step 7 | Go to Step 4 |
4 |
Does the test lamp illuminate in both RUN and ACC? | Go to Step 5 | Go to Step 8 |
5 |
Does the test lamp illuminate for either test? | Go to Step 6 | Go to Step 10 |
6 |
Did you find and correct the condition? | Go to Step 15 | Go to Step 12 |
7 |
Did you find and correct the condition? | Go to Step 15 | Go to Step 9 |
8 |
Did you find and correct the condition? | Go to Step 15 | Go to Step 9 |
9 | Inspect for poor connections at the harness connector of the ignition switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 15 | Go to Step 13 |
10 | Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 15 | Go to Step 14 |
11 | Inspect for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 15 | Go to Step 12 |
12 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 15 | -- |
13 | Replace the ignition switch. Refer to Ignition and Start Switch Replacement . Did you complete the replacement? | Go to Step 15 | -- |
14 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 15 | -- |
15 |
Does DTC B1382 or B1383 reset? | Go to Step 1 | System OK |