Sonata GL V6-3.0L (1997)
(The PCM is decreasing fuel delivery to compensate for a "Rich" condition)
^
Check the evaporative emission system. An intermittently sticking or stuck open purge solenoid may not set an evaporative code in a 1996 or 1997
SOHO Accent or Sonata, but may set a Fuel Trim code.
^
Check the air flow sensor calibration. If no vacuum leaks are present and the purge system is functioning properly, compare the air flow sensor
reading at idle and at 2500 rpm to the Air Flow Sensor Table. If readings are out of specification, swap the air flow sensor with a known good unit
and re-test.
^
Check the fuel pressure (for high pressure), the fuel flow (for a return line restriction), the injector part number, the PCM part number and perform
the oxygen sensor scan tool test as noted in this TSB.
Note:
For 1996 Accent SOHC with diagnostic code P1123 only, refer to TSB # 96-36-004 (Powertrain Control Module EPROM Replacement Procedure).
Note:
The table is supplied as general reference information. If the Fuel Trim conditions occur at different RPM, compare the air flow sensor reading to a
known good vehicle. A "new" vehicle or sensor may read a slightly higher value than normal.
Oxygen Sensor Scan Tool Testing Procedure
1.
A. Connect the scan tool
B. Warm up the vehicle to operating temperature (for at least 3 minutes)
C. Select vehicle, year, VIN code, etc.
D. Select "Engine"
E. Select "Data"
F. After OBD II data appears, press "N"
G. Select "Custom Data List"
H. Select "02-B1-S1" and "O2-B1-S2" (front and rear oxygen sensors) and ENG RPM if no tachometer is available.
I.
Press "N" and the selected data will appear
2.
While holding the engine speed at 2500 rpm in "Neutral" or "Park" (with no load) observe the front and rear oxygen sensors for approximately one
minute. The front oxygen sensor should fluctuate rapidly between 0.095 and 0.995 V. The voltage should read higher than 0.600 V several times
and lower than 0.350 V several times. The voltage should never exceed 1.00 V when using the scan tool.
If an Accent, Elantra or Tiburon front or rear oxygen sensor reads a fixed value of 0.425 V to 0.500 V, or a Sonata reads a fixed value of 0.010 to
0.080 V, check for an open/shorted oxygen sensor circuit or no output from the sensor.
The scan tool can also be used to check the sensors while the vehicle is being driven. An assistant is needed to perform this procedure. Use the scan tool
as set up in the previous test procedure.
1.
While driving in first gear, accelerate so the engine speed is near 4000 rpm. Quickly release the accelerator and observe the readings from both
sensors. The sensors, should read lean (in the range of 0.20 V down to 0 V) on the scan tool due to the fuel cut-off during deceleration.
2.
While driving in first gear, accelerate hard and observe both sensors. The sensors should read rich (in the range of 0.60 V to 1.0 V) on the scan
tool.
