Pinpoint Test F: DTC P1643; CHECK THE TCM SUPPLIES AND GROUNDS

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Jaguar XKR, 2006 Jaguar XK8, 2005 Jaguar XKR, 2005 Jaguar XK8, and 2004 Jaguar XKR. However, it is still accessible from the selected car via links, so may be relevant.

CHECK THE PERMANENT POWER SUPPLY TO THE TCM
Turn the ignition switch to the OFF position.

Disconnect the TCM electrical connector, GB02.

Measure the voltage between GB02, pin 14 (NR) and GROUND.

Is the voltage less than 10 volts?

YES: REPAIR the circuit between the TCM and battery. This circuit includes the engine management fuse box, (fuse 4) and the high power protection module. For additional information, refer to the wiring diagrams. Test the system for normal operation.

NO: Go to step 2.
CHECK THE IGNITION SWITCHED POWER SUPPLY TO THE TCM
Turn the ignition switch to the ON position.

Measure the voltage between GB02, pin 09 (WB) and GROUND.

Is the voltage less than 10 volts?

YES: REPAIR the circuit between the TCM and battery. This circuit includes the engine compartment fuse box, (fuse 1) the ignition positive relay and the high power protection module. For additional information, refer to the wiring diagrams. Test the system for normal operation.

NO: Go to step 3.
CHECK THE PERMANENT GROUNDS TO THE TCM
Measure the resistance between GB02, pin 13 (B) and GROUND.

Measure the resistance between GB02, pin 16 (B) and GROUND.

Is either resistance greater than 5 ohms?

YES: REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. Test the system for normal operation.

NO: If the CAN tests are satisfactory, contact dealer technical support for advice on possible TCM failure.