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.
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HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 85 (ENGINE CONTROLS - SELF-DIAGNOSTICS - 2.2L)DIAGNOSTIC TESTSDTC P0135: HO2S1 HEATER PERFORMANCEDTC PARAMETERS
1999 GMC Forward Control 5.7 R, Automatic
DTC Parameters
1999 GMC Forward Control 5.7 R, AutomaticSECTION DTC Parameters
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Engine run time is greater than 60 seconds.
- ECT is greater than 158°F (70°C).
- Ignition voltage greater than 10V.
- Air flow less than 25 g/s (M/T) or 40 g/s (A/T).
- Fuel level greater than 10%.
- No CKP, ECT, EVAP, fuel injector, fuel tank pressure, fuel trim, IAT, idle speed, MAP, misfire, ECM internal fault, or TP sensor DTCs have been set.
DTC P0135 will set if HO2S1 heater current is less than 0.2A or greater than 1.5A.
RENDER: 1.0x
NO RELATED
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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.