NOTE
Be sure the battery is fully charged.

Main Harness [B] Oxygen Sensor [C]
Special Tool - Measuring Adapter: 57001-1700
Oxygen Sensor Heater Power Source Voltage Connections to Adapter: Digital Meter (+) → R (main harness W/R) lead Digital Meter (–) → Frame Ground terminal

Power Source Voltage Standard: Battery Voltage
If the reading is in specification, but the problem still exists, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
If the reading is out of the standard, check the following.
ECU Relay Fuse 15 A (see Fuse Inspection in the Electrical System chapter) Power Source Wiring (see Oxygen Sensor Circuit)
If the fuse and wiring are good, remove the ECU and check the wiring for continuity between harness connectors.
Special Tool - Hand Tester: 57001-1394
Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection ECU Connector [A] ←→ Oxygen Sensor Connectors [B] R lead (ECU terminal 76) [C]
If the wiring is good, check the ECU for its ground and power supply (see ECU Power Supply Inspection in the Fuel System (DFI) chapter).
If the ground and power supply are good, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
Oxygen Sensor Circuit

1. ECU
2. Oxygen Sensor
3. Ignition Switch
4. Joint Connector F
5. Joint Connector A
6. Fuse Box 1
7. Ignition Fuse 15 A
8. Relay Box
9. ECU Main Relay
10. Frame Ground 3
11. Starter Relay
12. ECU Fuse 15 A
13. Main Fuse 30 A
14. Battery
15. Engine Ground
Oxygen Sensor Heater Resistance Inspection
KIBS Hydraulic Unit Communication Error (Service Code 1b, KIBS Equipped
Models)DFI Servicing Precautions
There are a number of important precautions that should
be followed servicing the DFI system.
This DFI system is designed to be used with a 12 V sealed
battery as its power source. Do not use any other battery
except for a 12 V sealed battery as a power source.
Do not reverse the battery ...
Fuel Pressure Inspection
NOTE
Be sure the battery is fully charged.
Remove:
Fuel Tank Covers (see Fuel Tank Removal)
Fuel Tank Bolts (see Fuel Tank Removal)
Primary Fuel Hose (see Fuel Hose Replacement in the
Periodic Maintenance chapter)
Be sure to place a piece of cloth around the fuel outlet
pipe of the ...
Service Code Reading
The service code(s) is displayed on the LCD by the number
of two digits.
NOTE
The service code of the KIBS and ABS adds “b” at the
left side of the code.
The service code of the ESD adds “E” at the left side of
the code.
When there are a number of problems, all the serv ...