How to fix vats on 98 sonoma
What's wrong with it , have you had it checked for DTC'S - diagnostice trouble codes .
The design of the passlock™ system is to prevent the vehicle operation if the proper ignition key is not used in order to start the vehicle. The mechanical key, in normal operation, will turn the passlock™ lock cylinder. The passlock™ sensor will relay the passlock™ data to the body control module (BCM). The BCM will determine the validity of the passlock™ data. The BCM will send a code password to the vehicle/powertrain control module (VCM/PCM). When the VCM/PCM receives the correct code the VCM/PCM allows the fuel injectors to operate normally. The passlock™ system requires the VCM/PCM and the BCM to communicate the various functions in order to operate. These functions transmit over the class 2 serial data line CKT 1807. For an explanation of the class 2 serial data operation refer to Data Link Connector Circuit Description in Wiring Systems.
ON constant for 3 seconds, then OFF
The bulb check occurs upon power-up (Ignition 1 and crank).
ON constant for 3 seconds, OFF momentarily, ON constant/ignition OFF
DTC (current) is set with the ignition ON (see DTC B2947, B2948, B2957 and B2958).
ON constant/ignition OFF
The TBC fuse is open or an open in CKT 1140
ON constant for 3 seconds, FLASH for 10 minutes, then OFF
Occurs when a Passlock™ sensor has been replaced and the ignition switch has been turned from the OFF position to the CRANK position. This sequence occurs 3 times.
FLASH with the ignition ON
The Passlock system is in a tamper mode (see DTC B2960 and B3033).
ON constant for 3 seconds, OFF momentarily, then ON constant for 10 minutes, then OFF
Occurs when a new BCM or a new PCM/VCM has been installed, and the ignition switch has been turned from the OFF position to the CRANK position. This sequence occurs 3 times.
ON constant for 3 seconds, OFF for 2 seconds, then ON constant
The IPC is unable to communicate with the BCM.
DTC B2947 Security System Sensor Power CKT Low
DTC B2948 Security System Sensor Power CKT High
DTC B2957 Security System Sensor Data Circuit Low
DTC B2958 Security System Sensor Data Circuit High
DTC B2960 Sec Sys Sensor Data Incorrect but Valid
DTC B3031 Security System Controller in Learn Mode
DTC B3033 Security System Indicates Tamper .
Your best bet , take your vehicle to a qualified repair shop .
1998 GMC Sonoma
on Feb 20, 2017