Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Vehicles Without Navigation
Information and Entertainment System
Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Vehicles Without Navigation
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information Electrical Diagrams.
Normal Operation
The Audio Front Control Module (ACM) directs audio signals to the speakers in the form of an AC voltage. The ACM (Audio Front Control Module) provides internal circuit protection for shorts to ground or shorts to voltage. The tweeter speakers are integral to the front door speakers and cannot be replaced separately.
A short to ground or short to voltage in the circuitry to one of the speakers can cause multiple speakers to lose sound due to the built-in overload protection feature of the ACM (Audio Front Control Module). In this case, a speaker fault DTC sets, and this pinpoint test should be followed to isolate the damaged circuit.
It should also be noted that when the ACM (Audio Front Control Module) activates the built-in overload protection, DTC B1342 can also set. The circuit failure must be repaired before DTC B1342 can be cleared.
- DTC B2965 (Audio System Speaker Circuit Fault)- sets when an open, short to ground, or short to voltage is detected on any of the speaker circuits.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- ACM (Audio Front Control Module)
PINPOINT TEST B : POOR QUALITY/DISTORTED/NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS) - VEHICLES WITHOUT NAVIGATION
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
B1 CHECK THE AUDIO SIGNALS TO THE SUSPECT SPEAKER
- Ignition OFF.
- Disconnect: Suspect Speaker.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage between the suspect speaker pin 1 and pin 2, harness side as follows:
Suspect Speaker Positive Meter Lead Negative Meter Lead LF door C523-1 VME07 (WH) C523-2 RME07 (WH/BN) RF door C612-1 VME10 (WH/VT) C612-2 RME10 (WH/OG) LR door C702-1 VME12 (BN/WH) C702-2 RME12 (BN/BU) RR door C802-1 VME12 (BN/WH) C802-2 RME12 (BN/BU)
Is a fluctuating AC voltage present?
Yes
INSTALL a new speaker for the suspect speaker. REFER to Speaker - Door . CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B2.
B2 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM (Audio Front Control Module) C240A.
- Ignition ON.
- Measure the voltage between the suspect speaker, harness side and ground as follows:
Suspect Speaker Positive Meter Lead Negative Meter Lead LF door C523-1 VME07 (WH) Ground C523-2 RME07 (WH/BN) Ground RF door C612-1 VME10 (WH/VT) Ground C612-2 RME10 (WH/OG) Ground LR door C702-1VME12 (BN/WH) Ground C702-2 RME12 (BN/BU) Ground RR door C802-1 VME12 (BN/WH) Ground C802-2 RME12 (BN/BU) Ground
Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. REPEAT the self-test.
No
GO to B3.
B3 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the suspect speaker, harness side and ground as follows:
Suspect Speaker Positive Meter Lead Negative Meter Lead LF door C523-1 VME07 (WH) Ground C523-2 RME07 (WH/BN) Ground RH front C612-1 VME10 (WH/VT) Ground C612-2 RME10 (WH/OG) Ground LH rear C702-1 VME12 (BN/WH) Ground C702-2 RME12 (BN/BU) Ground RH rear C802-1 VME12 (BN/WH) Ground C802-2 RME12 (BN/BU) Ground
Are the resistances greater than 10,000 ohms?
Yes
GO to B4.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
B4 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR AN OPEN
- Measure the resistance between the ACM (Audio Front Control Module), harness side and the suspect speaker, harness side as follows:
Suspect Speaker Positive Meter Lead Negative Meter Lead Circuit LF door C240A-8 C523-1 VME07 (WH) C240A-21 C523-2 RME07 (WH/BN) RF door C240A-11 C612-2 VME10 (WH/VT) C240A-12 C612-2 RME10 (WH/OG) LR door C240A-9 C702-1 VME09 (WH/GN) or VME12 (BN/WH) C240A-22 C702-2 RME09 (BN/YE) RR door C240A-10 C802-2 VME12 (BN/WH) C240A-23 C802-2 RME12 (BN/BU)
Are the resistances less than 5 ohms?
Yes
GO to B5.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
B5 CHECK FOR CORRECT ACM (Audio Front Control Module) OPERATION
- Connect: All Disconnected Connectors.
- Disconnect all the ACM (Audio Front Control Module) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM (Audio Front Control Module) connectors and make sure they seat correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes
INSTALL a new ACM (Audio Front Control Module). REFER to 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. CLEAR any DTCs present.