Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

1. 1
   
   The Diagnostic System Check - Engine Controls prompts the technician to complete some basic checks and stores the Freeze Frame/Failure Records data on the scan tool if applicable. This creates an electronic copy of the data that was taken when the malfunction occurred. The information is then stored in the scan tool for later reference.
2. 3
   
   The TP sensor may be able to auto zero itself after several engine starts if the sensor is stuck, but may not be able to reach the sensors range about 100 percent. The TP angle should increase steadily. If the voltage value spikes high or low, consider the test failed.
3. 4
   
   The TP sensor has an auto zeroing feature. If the voltage reading is 0.2-0.9 volt, the PCM will assume the TP sensor is at a closed throttle position of 0 percent. If the reading is out of the auto zeroing range at closed throttle, look for a binding or damaged linkage.
4. 6
   
   While starting the engine, the MAP sensor should detect any changes in manifold pressure. This test is to determine if the sensor is stuck at a value.
5. 7
   
   A normal MAP sensor will react as quickly to the throttle changes as they can be made. A MAP sensor should not appear to be lazy or catch up with the throttle movements.
6. 28
   
   Spread terminals or faulty electrical connections can produce normal results when the circuits are probed but cause incorrect readings when the circuits are connected. Be sure to check all terminals for this condition.