Pinpoint Test AO: DTC B1318 Or DTC U3003:16 (Audio Control Module (ACM))
Information and Entertainment System
Pinpoint Tests
Pinpoint Test AO: DTC B1318 Or DTC U3003:16 (Audio Control Module (ACM))
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number
Normal Operation
- DTC B1318 (Battery Voltage Low) - set by the non-navigation Audio Control Module (ACM) as a continuous or on-demand DTC when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.
- DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold) - set by the navigation ACM as a continuous or on-demand DTC when the supply voltage falls below 10 volts for at least 10 seconds during normal operation, or for greater than 250 milliseconds during the self-test.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- High circuit resistance
- ACM
PINPOINT TEST AO: DTC B1318 OR DTC U3003:16 (ACM)
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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AO1 RECHECK THE ACM DTCs
- Clear the ACM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Repeat the ACM self-test.
- Is DTC B1318 or DTC U3003:16 still present?
Yes
GO to AO2.
No
The system is operating correctly at this time. The DTC may have set due to a previous low battery voltage condition.
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AO2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM
- Retrieve the continuous memory DTCs from all modules.
- Is DTC P0620, P0622, P0625, P0626, or P065B set in the PCM?
Yes
REFER to Charging System.
No
GO to AO3.
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AO3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE
- Check the battery condition and verify that the battery is fully charged. Refer to Battery.
- Is the battery OK and fully charged?
Yes
GO to AO4.
No
REFER to Battery.
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AO4 CHECK THE ACM VOLTAGE SUPPLY
- Ignition OFF.
- Measure and record the voltage at the battery.
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the ACM C240a-1, circuit SBP39 (WH/RD), harness side and ground.
- Is the voltage within 0.2 volt of the recorded battery voltage?
Yes
GO to AO5.
No
REPAIR the circuit for high resistance. CLEAR the DTCs. REPEAT the self-test.
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AO5 CHECK THE ACM GROUND CIRCUIT FOR CONTINUITY
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the ACM C240a-13, circuit GD114 (BK/BU), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to AO6.
No
REPAIR the circuit for high resistance. CLEAR the DTCs. REPEAT the self-test.
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AO6 CHECK FOR CORRECT ACM OPERATION
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM connectors and make sure they seat correctly.
- Is the concern still present?
Yes
INSTALL a new ACM. REFER to Audio Control Module (ACM) Audio Control Module (ACM). TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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