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

Information and Entertainment System

Pinpoint Tests

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

Normal Operation
- DTC B1318 (Battery Voltage Low) - set by the Accessory Protocol Interface Module (APIM) (V1) 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 APIM (V2) when the supply voltage 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 AG: 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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AG1 RECHECK THE APIM DTCs


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

Yes
GO to AG2.

No
The system is operating correctly at this time. The DTC may have been set due to a previous low battery voltage condition.

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AG2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM


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

Yes
REFER to Charging System.

No
GO to AG3.

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AG3 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 AG4.

No
REFER to Battery.

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AG4 CHECK THE APIM VOLTAGE SUPPLY


- Ignition OFF.
- Measure and record the voltage at the battery.
- Disconnect: APIM C3342.
- Ignition ON.
- Measure the voltage between the APIM C3342-1, circuit SBB41 (RD), harness side and ground.




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

Yes
GO to AG5.

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

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AG5 CHECK THE APIM GROUND CIRCUITS FOR CONTINUITY


- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the APIM C3342-37, circuit GD114 (BK/BU), harness side and ground; and between the APIM C3342-38, circuit GD114 (BK/BU), harness side and ground.




- Are the resistances less than 5 ohms?

Yes
GO to AG6.

No
REPAIR the circuit in question for high resistance. CLEAR the DTCs. REPEAT the self-test.

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AG6 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.
- Operate the system and verify the concern is still present.
- 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. CLEAR the DTCs.

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