Vehicle Surges Or CHUGGLES: Sensor/System
- Monitor the Heated Oxygen Sensors (HO2S). The HO2S should respond quickly to different throttle positions. If not, check the HO2S for silicone or other contaminants from fuel or use of improper RTV sealant. The sensors may have a White powdery coating. Silicone contamination causes a high but false HO2S signal voltage, rich exhaust indication. The Powertrain Control Module (PCM) reduces the amount of fuel delivered to the engine, causing a severe driveability problem.
- Check MAF sensor and related wiring.
- Check the air intake ducts for being collapsed, damaged areas, looseness, improper installation, or leaking especially between the Mass Airflow (MAF) sensor and the throttle body.
- Monitor the 24X crank sensor and CMP sensor signal present parameters on the scan tool. If both are not responding, test the sensor feed circuit. Both sensors use a separate feed circuit but are internally connected to power. Check all CKP sensor "A" and CMP sensor circuits for intermittents. See INTERMITTENTS .
- Monitor the 3X crank sensor parameter on the scan tool. If the 3X crank sensor parameter is not responding, check the CKP sensor "B" and circuits for intermittents. Check the Ignition Control (IC) circuit, IC timing control circuit, low resolution engine speed signal circuit and the low reference circuit for intermittents. If these circuits become open, or shorted may not set a DTC immediately, but are capable of causing driveability complaints. See INTERMITTENTS .
- Check the Exhaust Gas Recirculation (EGR) system for proper operation. See EXHAUST GAS RECIRCULATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - 3.1L CENTURY, GRAND PRIX & MALIBU article.