Scan Tool - Wrong Absolute Pressure Sensor Output

Classification:
EC97-044

Reference:
NTB98-006

Date:
February 1, 1998

Subject:
1997 TRUCK - CONSULT UNABLE TO MONITOR ABSOLUTE PRESSURE SENSOR

APPLIED VEHICLE:
All 1997 Truck (D21)

SERVICE INFORMATION

CONSULT cannot monitor output voltage from the absolute pressure sensor on 1997 Trucks.





If you select absolute pressure sensor in CONSULT Data Monitor mode, the voltage values on the screen will be from the EVAP control system pressure sensor.





If you need to monitor the absolute pressure sensor voltage on a 1997 Truck, monitor the blue (L) wire between the absolute pressure sensor (terminal # 2) and ground or the ECM (terminal # 57) and ground with a digital multimeter. Figure 2 shows a typical voltage check at the absolute pressure sensor connector on the engine.

CAUTION:
Be careful not to damage the wire insulation, shield or electrical terminals when you check the voltage.