Ford ST3093-A Instructions Manual page 8

419-11-8
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST A: THE COMPASS IS INOPERATIVE (Continued)
A6 CHECK THE COMPASS SIGNAL CIRCUIT FOR AN OPEN OR SHORT TO GROUND (Continued)
• Is the resistance less than 5 ohms between the auto-dimming
interior mirror and the IPC, and greater than 10,000 ohms
between the auto-dimming interior mirror and ground?
A7 CHECK THE COMPASS SIGNAL RETURN CIRCUIT FOR AN OPEN OR SHORT TO GROUND
• Measure the resistance between the auto-dimming interior mirror,
harness side and the IPC, harness side; and between the auto-
dimming interior mirror, harness side and ground as follows:
Option Content
Without camera
mirror, without SYNC
Without camera
mirror, with SYNC
With camera mirror
Electronic Compass
Positive Meter Lead Negative Meter
Lead
C911-7 C220-9
VMC30 (BU/GY) VMC30 (BU/GY),
then ground
C9012-2 C220-9
VMC30 (BU/GY) VMC30 (BU/GY),
then ground
C9039-10 C220-9
VMC30 (BU/GY) VMC30 (BU/GY),
then ground
2011 Mustang, 2/2011
Yes
GO to A8.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the
self-test.
419-11-8