Toyota 4-Runner 1985 Repair Manual page 240

EFI SYSTEM - Electronic Control System
FI-71
CONTINUED
FROM PAGE FI- 72
Measure voltage.
I
Re-warm the Ox sensor
2,500 rpm.
Is there 3.75 V or more
YES
Repair
with the engine
running?
NO
Check for a short or open
Short or open circuit
Repair
circuit in the wiring between
the Ox sensor and ECU.
j
After turning off the
Lean
Replace ECU.
engine, re-start without
depressing the accelerator
pedal.
Open circuit
Replace Ox sensor. I