6E1-22
ENGINE AND EMISSION CONTROL SYSTEM
SH410
CODE NO.14 (P0130) OXYGEN SENSOR CIRCUIT
(SIGNAL VOLTAGE DOESN’T CHANGE)
NOTE:
Before diagnosing trouble according to flow table
given below, check to make sure that following sys-
tem and parts other than Electronic Fuel Injection
system are in good condition.
– Air cleaner (clogged)
– Vacuum leaks (air inhaling)
– Spark plugs (contamination, gap)
– High-tension cords (crack, deterioration)
– Ignition timing
– Engine compression
– Any other system and parts which might affect A / F
mixture or combustion.
If code No.14 (P0130) and another code No. are indi-
cated together, the latter has priority. Therefore,
check and correct what is represented by that code
No. first and then proceed to the following check.
Be sure to use a voltmeter with high impedance
(M
/ V minimum) or digital type voltmeter for accu-
rate measurement.
1. ECM (PCM)
2. Oxygen sensor
3. Connector
STEP
ACTION
YES
NO
1
1) Warm up engine to normal operat-
ing temperature.
2) Connect voltmeter between E02-13
terminal of ECM coupler and body
ground.
3) Maintain engine speed at 2000 rpm
and after 60 seconds, check volt-
meter.
Does the voltage deflect between
above and below 0.45 V repeatedly?
Oxygen sensor and its circuit
(closed loop system, A/F ratio feed
back system) are in good condition.
Intermittent trouble or faulty ECM
(PCM).
Recheck, referring to INTERMIT-
TENT AND POOR CONNECTION
in SECTION 0A.
Go to Step 2.
2
Does the voltage remain unchanged at
0.45 V above?
“Bl” circuit shorted to power circuit
or rich A/F mixture.
If circuit is OK, check MAP sensor,
ECT sensor, fuel pressure, injectors
and their circuit. If all above are OK,
check ECM (PCM) and its circuit.
Go to Step 3.
3
1) Maintain engine speed at 2000 rpm
for 60 seconds.
2) Check voltmeter while repeating
racing engine.
3) Does it indicate 0.45 V or more
even once?
Poor E02-13 connection or lean
A / F mixture.
If connection is OK, check MAP
sensor, ECT sensor, fuel pressure,
injectors and their circuit.
If all above are OK, check ECM and
its circuit.
“Bl” circuit open/short or
oxygen sensor malfunc-
tion.
If wire and connection are
OK, replace oxygen sen-
sor and recheck.