Sonata GL V6-3.0L (1997)
^
The Sonata engine management system will only set one Fuel Trim code. Code P0170 will set when the "Long Term" Fuel Trim values are "Rich" or
"Lean" beyond the programmed limits.
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The "Long Term" Fuel Trim correction range is -12.5% to +12.5% on Sonata vehicles. If the "Long Term" Fuel Trim value exceeds this range in two
consecutive trips, a code will be stored in the PCM.
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The Fuel Trim values will indicate if the PCM is compensating rich or lean. A PCM that is increasing fuel delivery (to compensate for a "Lean"
condition) will have a positive (+) "Long Term" Fuel Trim number. A PCM that is decreasing fuel delivery (to compensate for a "Rich" condition)
will have a negative (-) "Long Term" Fuel Trim number.
Fuel Trim Code Troubleshooting Tips
1.
Using the HDS scan tool, access and write down the Freeze Frame Data (which is the data stored at the time the diagnostic code was set). This
information can give valuable clues about the operating conditions at the time the code occurred and may reduce the amount of diagnosis and
testing required to repair the vehicle.
A.
Connect the scan tool and identify the vehicle.
B.
Select 1, ENGINE" under the "Select System " menu.
C.
Select CODES & DATA MENU from the engine "Main Menu".
D.
Select FREEZE FRAME to retrieve the engine operating conditions that were present at the moment the DTC was set.
2.
Check the vehicle to identify if codes other than Fuel Trim codes or driveability symptoms are present. A malfunction of any of the following
components may affect the Fuel Trim values:
^
Oxygen Sensors
^ Air Flow Sensor
^
Evaporative Emission System
^ Coolant Temperature Sensor
^
Intake Air Temperature Sensor
^ Fuel Injector
^
Throttle Position Sensor
If codes other than Fuel Trim codes are present, diagnose/repair these conditions before continuing with Fuel Trim diagnosis.
DTC P1124,1128, or P0170 (Positive Fuel Trim Numbers
(The PCM is increasing fuel delivery to compensate for a "Lean" condition)
^
Check for vacuum or unmetered air leaks, concentrating on areas between the air flow sensor and the engine block. Are all the gaskets and hoses
properly installed? A vehicle with a vacuum leak will have an air flow sensor reading that is lower than normal at idle (see Air Flow Sensor Table in
this TSB). Accent, Elantra and Tiburon vehicles with a vacuum leak may also have a low load value.
^
Check the evaporative emission system. An intermittently sticking or stuck open purge solenoid valve may not set an evaporative code in a 1996 or
1997 SOHC 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 low pressure), fuel volume flow (replace fuel filter if necessary), injector part number, PCM part number and perform
the oxygen sensor scan tool test as noted in this TSB.
DTC P1123,1127 or P0170 (With Negative Fuel Trim Number
