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Security Lamp Illuminated on the IP, Engine Stalls, No Start, DTC B2960 (Security System Sensor Data Incorrect but Valid) Set (Inspect and Repair Cause of DTC B2960)

Subject:Security Lamp Illuminated on the IP, Engine Stalls, No Start, DTC B2960 (Security System Sensor Data Incorrect but Valid) Set (Inspect and Repair Cause of DTC B2960)

Models:1998-2001 Chevrolet and GMC G-Van Models


Condition

Some customers may comment on the following conditions. These symptoms may be intermittent.

    • Security lamp illuminates while driving. The Security lamp may be On or Off when the customer brings the vehicle to the repair facility.
    • The engine cranks but will not start and the Security lamp is flashing.
    • The engine starts then stalls and the Security lamp is flashing.

Cause

Condition(s) may be due to an incorrect Passlock™ sensor voltage received by the Passlock™ module due to the following conditions. Most intermittent conditions are caused by faulty electrical connections or wiring.

    • A 7 ohm variation in the sensor ground circuit wiring, circuit 1057
    • A 100 ohm variation in the Passlock™ sensor signal wiring circuit, circuit 1836

Inspect for the following items:

    • Broken wiring inside the insulation.
    • A poor connection between the male and female terminal at a connector. Refer to Testing for Proper Terminal Contact under Testing for Intermittent and Poor Connections in Wiring Systems for the specific procedure.
    • A poor terminal to wire connection. Some conditions that fall under this description include poor crimps, poor solder joints, crimping over the wire insulation instead of the wire itself, and corrosion in the wire to terminal contact area.
    • Wire insulation that is rubbed through. This causes an intermittent short as the bare area touches other wiring or parts of the vehicle.
    • A poor connection between the male and female terminal at a connector. This poor connection may be the result of contamination or deformation.
      • Contamination may be caused by the connector halves being improperly connected. A missing or damaged connector seal, damage to the connector itself, or exposing the terminals to moisture and dirt can also cause contamination. Contamination, usually in the underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit.
   - Separate the connector halves.
   - Visually inspect the connector halves for contamination. Contamination may result in a white or green build-up within the connector body or between terminals. This causes high terminal resistance, intermittent contact, or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety including the terminals, the seals, and the connector body.
      • Deformation is caused by probing the mating surface of a connector terminal without the proper adapter, improperly joining the connector halves, or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact causing an open or intermittently open circuit. Using an equivalent male terminal from the J 38125-B, test that the retention force is significantly different between a good terminal and a suspect terminal. Replace the female terminal in question.

Correction

Have any of the following components had service recently?

    • The Passlock™ Module
    • The ignition lock cylinder case assembly
    • The ignition switch
    • The PCM/VCM

If any of the above components have been replaced, the Passlock™ Reprogramming Seed and Key (10 Minute Re-Learn) procedure must be performed before any diagnostic procedures are performed.

To assist in diagnosis, the following steps are provided.

  1. Does the engine start? If not, use the Engine Cranks but Does Not Run diagnostic information in the Engine Controls sub-section of the applicable Service Manual.
  2. Observe the security indicator lamp in the instrument panel when you turn the key to the RUN position. Does the indicator lamp show any of the following conditions?
    3. • Lamp is On for 5 seconds, then goes Off. This is normal operation. The engine should start and run.
    • Lamp is On and does not go Off. A problem is detected but the engine starts. This indicates that the fault occurred when the engine was running.
    • Lamp does not come On. This is abnormal operation. Begin your diagnosis with A Diagnostic System Check - Theft Deterrent in the applicable Service Manual.
    • Lamp flashes On and Off. This indicates a problem has been detected this ignition cycle by the Passlock™ system and the engine may not start.

Important: You must diagnose the diagnostic trouble codes (DTCs) in the order specified in the DTC table shown below. Failure to do so may result in one or more of the following conditions:

   • Extended diagnostic time
   • Incorrect diagnosis
   • Incorrect parts replacement

Diagnostic Trouble Code

Description

Action

U1016 Current

Loss of Class 2 Communication with VCM

Data Link Communications System Check in Data Link Communications

U1255 Current

Class 2 Communication Malfunction

Data Link Communications System Check in Data Link Communications

C0559 Current

EEPROM Checksum Error

DTC C0559 EEPROM Checksum Error

B2947 Current

Security System Sensor Power Circuit Low

DTC B2947 Security System Sensor Power CKT Low

B3033 Current

Security System Indicates Tamper

DTC B3033 Security System Indicates Tamper

B2960 Current

Security System Sensor Data Incorrect But Valid

DTC B2960 Sec Sys Sensor Data Incorrect but Valid

B2957 Current

Security System Sensor Data Circuit Low

DTC B2957 Security System Sensor Data Circuit Low

B2958 Current or History

Security System Sensor Data Circuit High

DTC B2958 Security System Sensor Data Circuit High

B2948 Current

Security System Sensor Power Circuit High

DTC B2948 Security System Sensor Power High

B3031 Current

Security System Controller in Learn Mode

DTC B3031 Security System Controller in Learn Mode

B0688 Current

Security System Indicator Circuit High

DTC B0688 Security System Indicator Circuit High

To assist in diagnosis/repair, the following step by step instructions are provided:

  1. Install seat covers.
  2. Connect the scan tool to the diagnostic link connector (DLC).
  3. Enter scan tool diagnostics.
  4. Select the model year of the vehicle.
  5. Select light truck.
  6. Select F1, (Body).
  7. Select G for Series.
  8. Select F2, (Passlock™).
  9. Select F0, (Diagnostic Trouble Codes (DTC)).
  10. Select F0, (DTC information).
  11. Select F0, (Current DTC).
  12. Record on the repair order any current DTCs displayed. If none, skip the next step.
  13. Is a current B2960 DTC displayed? If no, the condition is not present with this key cycle. Continue to the next step.
  14. Select Exit.
  15. Select F1, (History DTC).
  16. Are any history DTCs other than B2960 present? If so, diagnose those DTCs first using the appropriate service information, otherwise continue.
  17. Select Exit.
  18. Select Exit.
  19. Select F1, (Data Display).
  20. Select F1, (Data).
  21. Cycle the ignition key to the OFF/LOCKED position and wait 20 seconds.
  22. Slowly turn the key to the RUN position but do not start the engine. Be careful not to turn the key into the START position.
  23. Observe the following values:
    24. • Passlock™ Data Voltage should be 5.0 volts.
    • Passlock™ State should be Normal.
    • Passlock™ Code should be Open.
  24. Rotate the key to the START position, and observe the following again:
    25. • Passlock™ Data Voltage should be less than 5.0 volts. Passlock™ should remain steady and not fluctuate. The test vehicle used for this diagnostic procedure had a voltage value of 2.49 volts. The vehicle being worked on may be either higher or lower than this value. The key is that it has to be less than 5.0 volts.
    • Passlock™ State should be "Monitor Passlock™".
    • Passlock™ Code should be Valid Code.
  25. If no trouble is found and the customer has experienced one of the symptoms or the code is a history DTC, the most likely cause is the Passlock™ wiring, specifically the wires from the Passlock™ sensor to the Passlock™ module.

    26. Caution: This vehicle is equipped with a Supplemental Inflatable Restraint (SIR) System. Failure to follow the correct procedure could cause the following conditions:

    1. Air bag deployment
    2. Personal injury
    3. Unnecessary SIR system repairs

  26. Open the hood. Install fender covers.
  27. Disconnect the negative battery cable.

    28. Object Number: 375631 Size: MF
  28. Loosen the screw holding the C200 (2) wiring harness connectors together. Separate the connection.

    29. Object Number: 306234 Size: SH
  29. Separate the turn signal and multifunction switch harness (2) from the 18-way connector (1). They have a locking tab in the center of each connector that needs to be released.

    30. Important: For all vehicles, use either the correct mating terminal, or electrical tool GM# 12094430, (J 38125-11A) (Blue) from the J 38125-B Terminal Repair kit. Perform a pull test to determine if the terminals have proper tension. If one is found where the tension is suspect, replace the terminal.

  30. Circuit number 1057, Orange with Black stripe wire, in cavity C4.

    31. Circuit number 812, Red with White stripe wire, in cavity B1.

    Circuit number 1836, Yellow wire, in cavity D3.

  31. On the end of the 18-way connector is the date the ignition switch wiring harness was manufactured. This date is etched in the plastic of the connector. It is displayed as two lines of numbers (i.e.: GM XXX, XXXX). The bottom row of four digits are the digits which must be verified. Do not be confused by the single row of four digits on one end of the connector. These digits are the connector part number. If two rows are not found, the following procedure must be performed. The following defines the four digits:
    32. • Month (1) Alpha Character (J = January, A = April, O = October, N = November, etc.)
    • Day (2) numbers (01-31)
    • Year (1) Number (9 =1999, 0 = 2000)
  32. If the date code is less than N080, (November 08, 2000), place a drop of solder to the wire and terminal interfaces on the wires in the following cavities:
    33. • Circuit number 1057, Orange with Black stripe wire, in cavity C4
    • Circuit number 812, Red with White stripe wire, in cavity B1
    • Circuit number 1836, Yellow wire, in cavity D3

    Object Number: 306234 Size: SH

    Important: Connector bolt torque is critical. Tightening the bolt to 7 N·m (61 lb in) may cause the pal nut of the connector to strip. Tightening the bolt less than 4 N·m (35 lb in) may result in an intermittent connection.

  33. Connect the 48-way connector (C200) to the vehicle's wiring harness. Tighten the screw holding the wiring harness connectors together.

    34. Tighten
    Tighten the screw holding the wiring harness connectors together to 6 N·m (53 lb in).

  34. Cycle the steering column tilt from full up to full down a minimum of ten times.
  35. Squeeze the ends of connector C200 together with your fingers, forcing the terminals and connector to properly seat together.
  36. Recheck the retaining screw for connector C200 torque.

    37. Tighten
    Tighten the screw holding the wiring harness connectors together to 6 N·m (53 lb in).

  37. Again, cycle the steering column tilt from full up to full down a minimum of ten times.
  38. Again, squeeze the ends of connector C200 together with your fingers, forcing the terminals and connector to properly seat together.
  39. Recheck the retaining screw for connector C200 torque.

    40. Tighten
    Tighten the screw holding the wiring harness connectors together to 6 N·m (53 lb in).

  40. Again, cycle the steering column tilt from full up to full down a minimum of ten times.
  41. Again, squeeze the ends of connector C200 together with your fingers, forcing the terminals and connector to properly seat together.
  42. Recheck the retaining screw for connector C200 torque.

    43. Tighten
    Tighten the screw holding the wiring harness connectors together to 6 N·m (53 lb in).

  43. Connect the negative battery cable.
  44. Observe the Security indicator lamp when the key is turned to the RUN position. The Security lamp should come On for 5 seconds then go Off. If it doesn't, you must recheck your work.
  45. Observe the SIR lamp. The lamp should be Off.
  46. Remove the seat covers.
  47. Remove the fender covers and close the hood.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

N6626

Wiring and/or Connector Repair - Theft Deterrent

0.7 hr