Pinpoint Test AF: DTC B1318 Or DTC U3003:16 (Accessory Protocol Interface Module (APIM))

Information and Entertainment System

Pinpoint Tests

Pinpoint Test AF: DTC B1318 Or DTC U3003:16 (Accessory Protocol Interface Module (APIM))

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 Accessory Protocol Interface Module (APIM) (V1) when the supply voltage on circuit SBB13 (GY/RD) falls below 10 volts for at least 10 seconds during normal operation.
- DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold) - set by the APIM (V2) when the supply voltage on circuit SBB13 (GY/RD) falls below 10 volts for at least 10 seconds during normal operation.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- High circuit resistance
- APIM



PINPOINT TEST AF: DTC B1318 OR DTC U3003:16 (APIM)

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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AF1 RECHECK THE APIM DTCs


- Clear the APIM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait at least 15 seconds.
- Repeat the APIM self-test.
- Is DTC B1318 or DTC U3003:16 still present?

Yes
GO to AF2.

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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AF2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM


- Retrieve the continuous memory DTCs from all modules.
- Is DTC P0620, P0622, P0625, or P065B set in the PCM?

Yes
REFER to Charging System.

No
GO to AF3.

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AF3 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 AF4.

No
REFER to Battery.

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AF4 CHECK THE APIM VOLTAGE SUPPLY


- Ignition OFF.
- Measure and record the voltage at the battery.
- Disconnect: APIM C3338.
- Ignition ON.
- Measure the voltage between the APIM C3338-1, circuit SBB13 (GY/RD), harness side and ground.




- Is the voltage within 0.2 volt of the recorded battery voltage?

Yes
GO to AF5.

No
REPAIR the circuit for high resistance. CLEAR the DTC. REPEAT the self-test.

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AF5 CHECK THE APIM GROUND CIRCUIT


- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the APIM C3338-37, circuit GD148 (BK/YE), harness side and ground; and between the APIM C3338-38, circuit GD148 (BK/YE), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to AF6.

No
REPAIR the circuit in question for high resistance. TEST the system for normal operation.

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AF6 CHECK FOR CORRECT APIM OPERATION


- Disconnect the APIM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the APIM connector and make sure it seats correctly.
- Wait 2 minutes for the APIM to re-initialize.
- Is the concern still present?

Yes
INSTALL a new APIM. REFER to Accessory Protocol Interface Module (APIM) Accessory Protocol Interface Module (APIM). 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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