LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1870 (Engine Controls And Fuel - 3.5L (L66) - DTC P2227 To DTC P2649) >> DTC P2555 >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 1:  The Diagnostic System Check - Vehicle prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool, if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
  2. 3:  The normal voltage reading is approximately 0.67 volt. If the conditions for a DTC P2555 are present, the circuit voltage would default to 0 volts.
  3. 5:  This step checks for an open in the TAC module electrical grounds. The TAC module can not operate correctly if there are faulty electrical grounds.
  4. 8:  After replacing the TAC module, a new minimum throttle position and idle speed must also be established.
DTC P2555

Step Action Value(s) Yes No
Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views
1  Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Turn ON the ignition, leaving the engine OFF.
  2. Use the scan tool in order to clear the DTCs.
  3. Start and run the engine for 1 minute.
Is a DTC P2555 set?		 - Go to Step 4  Go to Step 3 
3 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the voltage on the TAC Module Power Inhibit Feedback parameter of the scan tool.
Is the voltage within the specified range?		 0.63-0.70 V Go to Intermittent Conditions Go to Step 4 
4
  1. Inspect for a short to voltage in the ETC motor inhibit circuit.
  2. Repair as necessary. Refer to Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 9  Go to Step 5 
5  Probe each throttle actuator control (TAC) module ground circuit with a test lamp connected to B+.
Did the test lamp illuminate on both ground circuits?		 - Go to Step 7  Go to Step 6 
6 Repair the open in the ground circuits of the TAC module. Refer to Wiring Repairs .
Did you complete the repair?		 - Go to Step 9  -
7
  1. Inspect for an intermittent or poor electrical connection at the TAC module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
  2. Repair as necessary. Refer to Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 9  Go to Step 8 
8 
  1. Replace the TAC module. Refer to Throttle Body Assembly Replacement .
  2. Perform the idle learn procedure. Refer to Idle Learn .
Did you complete the replacement?		 - Go to Step 9  -
9
  1. Use the scan tool in order to clear the DTCs.
  2. Start the engine.
  3. Operate the vehicle within the Freeze Frame conditions as specified or until the DTC P2555 diagnostic test has run. Refer to the Test Description above.
Does the DTC run and pass?		 - Go to Step 10  Go to Step 2 
10 With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
scientia non olet · About LEMON Manuals