Pinpoint Test A: CHECK THE FORWARD ALERT SWITCH

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2008 Jaguar S-Type, 2007 Jaguar S-Type, 2006 Jaguar S-Type, 2005 Jaguar S-Type, and 2004 Jaguar S-Type. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For a quick function check of the switch action, monitor the LED function as the switch is operated.

CHECK THE FORWARD ALERT SWITCH GROUND
Disconnect the forward alert switch electrical connector, FC43.

Measure the resistance between FC43, pin 09 (B) and GROUND.

Is the resistance greater than 5 ohms?

YES: REPAIR the high resistance circuit. For additional information, refer to the appropriate SYSTEM WIRING DIAGRAMS article. TEST the system for normal operation.

NO: Go to step 2.
CHECK THE FORWARD ALERT SWITCH TO ASCCM CIRCUIT FOR HIGH RESISTANCE
Disconnect the battery negative terminal. Refer to Battery Disconnect .

Disconnect the ASCCM electrical connector, FH107.

Measure the resistance between FC43, pin 07 (GW) and FH107, pin 12 (GW).

Is the resistance greater than 5 ohms?

YES: REPAIR the high resistance circuit. For additional information, refer to appropriate SYSTEM WIRING DIAGRAMS article. TEST the system for normal operation.

NO: Go to step 3.
CHECK THE FORWARD ALERT SWITCH TO ASCCM CIRCUIT FOR SHORT CIRCUIT TO GROUND
Measure the resistance between FC43, pin 07 (GW) and GROUND.

Is the resistance less than 10,000 ohms?

YES: REPAIR the short circuit. For additional information, refer to appropriate SYSTEM WIRING DIAGRAMS article. TEST the system for normal operation.

NO: Go to step 4.
CHECK THE FORWARD ALERT SWITCH GROUND CIRCUIT FOR SHORT TO B+
Measure the voltage between FC43, pin 06 (B) and GROUND.

Is the voltage greater than 3 volts?

YES: REPAIR the short circuit. This circuit includes the splice IPS 35. For additional information, refer to the appropriate SYSTEM WIRING DIAGRAMS article. TEST the system for normal operation.

NO: INSTALL a new forward alert switch. CLEAR the DTC. TEST the system for normal operation. If the DTC is repeated, contact dealer technical support for advice on possible ECM failure.