Troubleshooting the DFI System
There are two ways to inspect the DFI system. One is
voltage Check Method and the other is Resistance Check
(Voltage Check Method)
This method is conducted by measuring the input voltage
[B] to a sensor [A] first, and then the output voltage [C]
from the sensor.
Sometimes this method can detect a fault of the ECU.
Refer to each sensor inspection section for detail in this
Use a fully charged battery and a digital meter [D] which
can be read two decimal places voltage or resistance.
(Resistance Check Method)
This method is simple. No need for a fully charged battery
and the needle adapter. Just do the following especially
when a sensor [A] is suspect.
Turn the ignition switch OFF and disconnect the connec-
Inspect the sensor resistance, using a digital meter (see
each sensor inspection in this chapter).
Inspect the wiring and connectors [B] for continuity, using
the hand tester [C] (analog tester) rather than a digital
Special Tool - Hand Tester: 57001-1394
If the sensor, the wiring and connections are good, in-
spect the ECU for its ground and power supply (see this
chapter). If the ground and power supply are good, the
ECU is suspect. Replace the ECU.
FUEL SYSTEM (DFI) 3-23