C 1500 Truck 2WD V8-6.5L DSL Turbo VIN F (1998)
Security Lamp/Indicator: Technical Service Bulletins
Fuel - Cranks But Doesn't Start or Immediately Stalls
File in Section: 6E - Engine Fuel & Emission
Bulletin No.: 77-65-31
Date: February, 1998
Subject:
Vehicle Cranks But Does Not Start, or Starts and Immediately Stalls, Vehicle Theft Deterrent PASSLOCK Security Light May Be Illuminated, No
DTC's or Possible DTC P1626, P1630, P1631 Stored (Perform Diagnostic Procedures)
Models:
1998 C, K, G Models - with 6.5L Diesel Engines
(VINs S, F - RPOs L56, L65, L65-CMT)
Condition
Some owners of 1998 trucks equipped with the 6.5L diesel engine may comment on an engine no start or engine starts and immediately stalls. In
addition, the vehicle theft deterrent system (PASSLOCK) security light may be illuminated. The vehicle may not have any DTC's or possible DTC's
P1626, P1630, P1631 stored.
Do not replace the fuel injection pump for this condition.
Cause
The vehicle theft deterrent system (VTD), PASSLOCK, may have disabled the fuel system of the vehicle. For the 1998 model year, GM trucks are
equipped with the VDT system called PASSLOCK. If a fault occurs in the VTD system, the PCM will not receive the correct serial data from the
PASSLOCK module. Without the correct data, the PCM will not allow the fuel injection pump to deliver fuel. The vehicle theft deterrent system security
light may be illuminated and the vehicle will not start, or start and immediately stall.
Correction
Always perform an on board diagnostics (OBD) system check on the vehicle prior to any repairs. The OBD system check will help determine if a fault
exists in the VTD system, and if the VTD system is responsible for the no start condition.
Several different situations may be experienced when diagnosing the PASSLOCK VDT system. It is possible to monitor the operation of the VTD
system using the Tech 2. It is also possible under certain circumstances to have an active PASS LOCK VTD system (fuel disabled) and set no DTC's.
If the engine cranks but does not start, or starts and immediately stalls, use the Tech 2 to check for DTC's in each of the following two areas:
1.
Each subsystem in the Tech 2 (Powertrain or body)
2.
Class 2 DTC's (Under Class 2 diagnostic circuit check, which will display all codes)
The following DTC's may be present in PASSLOCK fault detection:
P CODES (Powertrain) P1626, P1630, P1631
B CODES (Body) 80688, B2947, B2948, B2957, B2958, B2960, B3031, B3033
C CODES (Chassis) C0599
U CODES (Communication, listed at the end of the P codes, Section 6, Book 4 and Section 9D, Book 1) U1016, U1026, U1192, U1255
If no DTC's are set, pursue the following Tech 2 diagnostic path:
1.
Powertrain
2.
Engine Data List 1 (Engine list number may vary by vehicle line)
3.
Data list parameter: VTD fuel disabled "ACTIVE"
If the word active is present during or immediately following cranking, a PASSLOCK fault exists (inactive indicates a properly operating PASSLOCK
system). Note that the Tech 2 parameter may revert to inactive and the security light will stop flashing approximately 5 seconds after the key is released
