Operation CHARM: Car repair manuals for everyone.
Home >> Ford >> 2003 >> Thunderbird V8-3.9L VIN A >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Pinpoint Tests >> Test G
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Test G

PINPOINT TEST G: THE AUDIO CONTROL MODULE (ACM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOL


Test G1-G2:






Test G2-G3:






Normal Operation
The ACM communicates with the diagnostic tool through the standard corporate protocol (SCP) communications network. Circuits 4-EG10 (GY/BK) and 5-EG10 (BU/YE) receive and transmit data from the ACM to the data link connector (DLC). Degraded SCP performance occurs if one bus line is open, shorted to ground or voltage, or if one but not all termination resistors are lost.

Possible Causes
- circuit 4-EG10 (GY/BK) open
- circuit 5-EG10 (BU/YE) open
- ACM C240c
- ACM
pro multis · About Operation CHARM