DTC Confirmation Test

Malfunction is detected when no EGR flow is detected by EGR temperature sensor under conditions that call for EGR. Possible causes are:

• EGR Volume Control Valve (EGR-VCV) circuit open or shorted.
• EGR-VCV stuck closed.
• Weak battery.
• EGR passage clogged.
• EGR temperature sensor or circuit fault.
• Exhaust leaks.

To set DTC, turn ignition off and wait at least 10 seconds. Turn ignition on and select MODE 1 with scan tool. Ensure engine coolant temperature is less than 104°F (40°C). While monitoring engine coolant temperature, start engine and let it idle. Measure voltage between ground and ECM terminal No. 91 (TP sensor signal) by backprobing. See Figure and Figure . When engine coolant temperature reaches 140°F (60°C), immediately drive vehicle at a suitable speed with engine at 1200-2400 RPM and TP sensor voltage at .65-1.08 volts for at least one minute. Repeat test and select MODE 3 with scan tool.