GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 PASS-Key Diagnostic System Check

Step

Action

Value(s)

Yes

No

1

Using a scan tool, attempt to establish communications with the BCM.

Can the scan tool communicate with the BCM?

--

Go to Step 2

Go to Diagnostic System Check - Body Control System

2

Using a scan tool, check if any of the following PASS-Key® DTCs are stored in the BCM memory:

    • DTC B2721
    • DTC B2722
    • DTC B2723
    • DTC B2735

Does the BCM have any of these DTCs stored?

--

Go to Diagnostic System Check - Body Control System

Go to Step 3

3
  1. Turn ON the ignition switch.
  2. Using a scan tool, select BCM Input Data 1 and display PASS-Key® state.

Does the scan tool display PASS-Key® state as Monitor Pass-key®?

--

Go to Step 6

Go to Step 4

4
  1. Using a scan tool, select BCM Input Data 1 and display PASS-Key® state.
  2. Check for the following PASS-Key® states:
    3. • Normal Decision
    • Fail Enable
    • Fail Enable Decision
    • Tamper

Did the scan tool display any of the indicated PASS-Key® states?

--

Go to Step 9

Go to Step 5

5
  1. Using a scan tool, select BCM Input Data 1 and display PASS-Key® state.
  2. Check for the following PASS-Key® states:
    3. • Auto Lrn Pend
    • Seed Lrn Pending
    • Auto Learn
    • Seed Key Learn

Did the scan tool display any of the indicated PASS-Key® states?

--

Go to Step 8

Go to Step 7

6
  1. Place the transmission in PARK (Auto Trans) or press the clutch (Manual Trans).
  2. Using a valid PASS-Key®, turn the ignition to the CRANK position and attempt to start the engine.

Does the engine crank?

--

System OK

Go to Step 10

7

Check for the following intermittent malfunctions:

    • Incorrect or damaged PASS-Key® resistor (must wait 3 minute time-out before attempting to try a different PASS-Key®.)
    • Foreign material on the PASS-Key® resistor
    • Poor connections or contacts at the ignition lock cylinder
    • An open or short on the PASS-Key® circuit

Was a problem found and repaired?

--

Go to Step 11

Go to Starting System Check

8

Program the PASS-Key® system. Refer to PASS-Key Programming .

Is the PASS-Key® system programmed?

--

Go to Step 11

--

9

Preform the ignition lock cylinder test. Refer to Ignition Lock Cylinder Test .

Was a problem found and repaired?

--

Go to Step 11

Go to Step 7

10

Locate and repair the malfunction in the engine cranking system. Refer to Starting System Check in Engine Electrical.

Is the repair complete?

--

Go to Step 11

--

11
  1. Turn OFF the ignition switch.
  2. Connect or install any connectors or components that were disconnected or removed.
  3. Clear all PASS-Key® DTCs. Refer to Clearing DTCs in Body Control System.

Is the repair complete?

--

System OK

--