The Powertrain Control Module (PCM) uses the camshaft position sensor to manage
sequential fuel injection and as part of misfire diagnosis. The PCM constantly monitors the
number of pulses on the signal circuit. The PCM compares the number of camshaft sensor
reference pulses and the number of crankshaft position sensor reference pulses received.
If the PCM receives an incorrect number of pulses, Diagnostic Trouble Codes (DTCs)
should be stored in the PCM. Some PCM systems will then default to multi-port or "gang-
fire" injector operation. The camshaft position sensor signal is required to sequence the
injector operation to the proper cylinder timing. If the camshaft position sensor or circuit is
faulty, most engines will start. However, the PCM misfire diagnostic will likely be affected.
Typical CMP sensor
HO
2
S
The heated oxygen sensor is used by the powertrain control module to measure the
amount of oxygen in the exhaust. The PCM uses this data to control the air fuel mixture in
the engine. The PCM sends a bias voltage of approximately 450 mV to the oxygen sensor.
At operating temperature the oxygen sensor signal varies between 0 and 1,000 mV. When
the mixture is rich the oxygen content is low and the voltage signal will remain on the high
side of the 450 mV mid-range. When the mixture is lean the oxygen content is high and
the voltage signal will remain on the low side below the 450 mV mid-range.
Summary of Contents for TrailBlazer
Page 1: ......
Page 26: ...Fig 3 Typical body and undervehicle maintenance locations Refer to chart for descriptions ...
Page 29: ......
Page 30: ......
Page 31: ......
Page 175: ...Spring free length check Valve spring squareness check ...
Page 192: ...Front of piston mark ...
Page 361: ...5 3L Engine Except Saab Underhood Fuse Block 2003 2005 Early Production ...
Page 469: ...Removing the outer band from the CV boot Removing the inner band from the CV boot ...
Page 470: ...Removing the CV boot from the joint housing Clean the CV joint housing prior to removing boot ...
Page 471: ...Removing the CV joint housing assembly Removing the CV joint ...
Page 472: ...Inspecting the CV joint housing Removing the CV joint outer snap ring ...
Page 473: ...Checking the CV joint snap ring for wear CV joint snap ring typical ...
Page 474: ...Removing the CV joint assembly Removing the CV joint inner snap ring ...
Page 475: ...Installing the CV joint assembly typical ...
Page 553: ...9 Torque the lug nuts to specification 10 Lower the vehicle ...
Page 556: ...Toe in Frame Misalignment Frame misalignment ...
Page 588: ...Bleeding caliper ...
Page 624: ...Manifold gauge set components Refrigerant recovery recycling station ...
Page 676: ...A C Specifications ...
Page 677: ......