Pinpoint Test A: Module Power And Ground Supplies

PINPOINT TEST A: MODULE POWER AND GROUND SUPPLIES

TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
A1: CHECK THE POWER SUPPLY FUSES	Make sure the ignition is turned off. Check fuses 04, 16 and 18 of the engine compartment junction box. Are the fuses in good condition? Yes Go to A2. No Install a new fuse as necessary. Check the system for normal operation. If the fuse fails again, check the circuit for a short to ground. Refer to SYSTEM WIRING DIAGRAMS for XJR or SYSTEM WIRING DIAGRAMS for XJ8.
A2: CHECK THE PERMANENT POWER SUPPLY (1) TO THE MODULE	Disconnect the ABS module connector, LF27. Measure the voltage between LF27, pin 09 and ground. Is the voltage greater than 10 volts? Yes Go to A3. No Repair the circuit between the engine compartment junction box, fuse 16 and LF27 pin 09. Refer to SYSTEM WIRING DIAGRAMS for XJR or SYSTEM WIRING DIAGRAMS for XJ8. Clear the DTC and check for normal operation.
A3: CHECK THE PERMANENT POWER SUPPLY (2) TO THE MODULE	Measure the voltage between LF27, pin 25 and ground. Is the voltage greater than 10 volts? Yes Go to A4. No Repair the circuit between the engine compartment junction box, fuse 18 and LF27 pin 25. Refer to SYSTEM WIRING DIAGRAMS for XJR or SYSTEM WIRING DIAGRAMS for XJ8. Clear the DTC and check for normal operation.
A4: CHECK THE IGNITION POWER SUPPLY TO THE MODULE	Make sure the ignition is on. Measure the voltage between LF27, pin 20 and ground. Is the voltage greater than 10 volts? Yes Go to A5. No Repair the circuit between the engine compartment junction box, fuse 04 and LF27 pin 20. Refer to SYSTEM WIRING DIAGRAMS for XJR or SYSTEM WIRING DIAGRAMS for XJ8. Clear the DTC and check for normal operation.
A5: CHECK THE GROUND SUPPLY TO THE MODULE	Makes sure the ignition is turned off. Measure the resistance between LF27, pin 08 and 24 and ground. Is the resistance less than 5 ohms? Yes The power and ground supplies to the module are OK. Recheck the DTCs for codes indicating a fault elsewhere. No Repair the high resistance circuit. Refer to SYSTEM WIRING DIAGRAMS for XJR or SYSTEM WIRING DIAGRAMS for XJ8. Clear the DTC and check for normal operation.