DTC 61 - Turbo Boost Sensor CKT High: Notes

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1994 GMC Yukon, 1994 GMC Suburban, 1994 GMC Pickup, 1994 GMC Cab & Chassis, and 1994 GMC C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The PCM sends a 5-volt reference signal to the boost sensor. As manifold pressure changes, the electrical resistance of the boost sensor also changes. By monitoring the sensor output voltage, PCM detects how much pressure is being produced by the turbocharger in the intake manifold. The PCM uses the boost sensor to control turbo boost and fuel at different loads. DTC 61 will set when:

Boost signal voltage is greater than 3.9 volts.
RPM is less than 3500. PCM will default to no turbo boost and poor performance.
NOTE: Test numbers refer to numbers on diagnostic chart.

This step determines if DTC 61 is the result of a hard failure or an intermittent condition.
This step simulates conditions for DTC 62. If the PCM recognizes the change, then the PCM, and the boost signal circuit are okay.
This step checks for an open in the ground circuit.