The fuel trim is related to the feedback compensation value, not to the basic injection time. The fuel trim includes the short–term fuel trim and the long–term fuel trim.
The short–term fuel trim is the short–term fuel compensation used to maintain the air–fuel ratio at stoichiometric air–fuel ratio. The signal from the heated oxygen sensor indicates whether the air–fuel ratio is rich or lean compared to the stoichiometric air–fuel ratio. This variance triggers a reduction in the fuel volume if the air–fuel ratio is rich, and an increase in the fuel volume if it is lean.
The long–term fuel trim is the overall fuel compensation carried out in long–term to compensate for a continual deviation of the short–term fuel trim from the central value, due to individual engine differences, wear overtime and changes in the operating environment.
If both the short–term fuel trim and the long–term fuel trim are lean or rich beyond a certain value, it is detected as a malfunction and the mil is illuminated.
Dtc no. |
Dtc detection condition |
Trouble area |
P0171 | When air–fuel ratio feedback is stable after warming up engine, fuel trim is considerably in error on lean side (2 trip detection logic) |
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P0172 | When air–fuel ratio feedback is stable after warming up engine, fuel trim is considerably in error on rich side (2 trip detection logic) |
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Hint
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Monitor description
Under the closed–loop fuel control, fuel injection amounts that deviate from the ecm’s estimated fuel amount will cause a change in the long–term fuel trim compensation value. This long–term fuel trim is adjusted when there are persistent deviations in the short–term fuel trim values. And the deviation from a simulated fuel injection amount by the ecm affects a smoothed fuel trim learning value which is the combination of smoothed short–term fuel trim (fuel feedback compensation value) and smoothed long–term fuel trim (learning value of the air–fuel ratio). When the smoothed fuel trim learning value exceeds the dtc threshold, the ecm interprets this as a fault in the fuel system and sets a dtc.
Example: the smoothed fuel trim leaning value is more than +35% or less than –35%, the ecm interprets this as a fail in the fuel system.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Wiring diagram
Refer to dtc p0130
Inspection procedure
1 Inspect stop lamp switch assy
Check that the stop light lights up when brake pedal is depressed and
turns off when the brake pedal
is released.
2 Inspect skid control ecu terminal voltage(stp terminal)
Disconnect skid control ecu connector.
measure voltage between termina ...
Installation with LATCH system
1 Widen the gap between the seat cushion and seatback slightly.
► Type A
2 Latch the hooks of the lower straps onto the LATCH anchors. If the child restraint
has a top tether strap, the top tether strap should be latched onto the top tether
strap anchor.
For owners in Canada: The symbol ...
Emergency towing
If a tow truck is not available in an emergency, your vehicle may be temporarily
towed using a cable or chain secured to the emergency towing eyelet. This should
only be attempted on hard surfaced roads for short distances at low speeds.
A driver must be in the vehicle to steer and operate the ...