Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
State, fuel trim
Depending on the prevailing circumstances when the frozen values were created, one of the following alternatives may be stored.
- no fuel trim, the start conditions have not been met
.
This condition occurs at the crank or immediately after start before fuel trim has started
- fuel trim with two probes
.
This situation occurs during driving when both probes are used during fuel trim (part load)
- no fuel trim, operation with predefined values
.
This situation occurs during hard acceleration or during fuel shut-off when there is no fuel trim and operation is under predefined values
- no fuel trim, operation with a system fault
.
This situation occurs when an earlier diagnostic trouble code (DTC) was stored that caused the fuel trim to be disabled
- fuel trim with one probe (front)
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This situation occurs at idling speed or during light acceleration when one probe (front) is used during fuel trim.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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