Engine - Revised Cranks But Will Not Run Chart: Overview

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 61-65-23

Date: May, 1996

SERVICE MANUAL UPDATE

Subject:
Section 6E3 - Driveability and Emissions - Revised Chart A-3 - Engine Cranks But Will Not Run

Models:
1988-95 Buick Skylark
1990-94 Chevrolet Beretta
1995 Chevrolet Cavalier
1987 Oldsmobile Calais
1988-91 Oldsmobile Cutlass Calais
1990-91 Oldsmobile Cutlass Supreme
1992-95 Oldsmobile Achieva
1988-95 Pontiac Grand Am
1990-91 Pontiac Grand Prix
1995 Pontiac Sunfire
with 2.3L Engine (VINs A, D, 3 - RPOs LG0, LD2, L40)

This bulletin is being issued to revise Section 6E3 of the 1987-95 2.3L engine application service manuals. The Chart A-3 Engine Cranks But Will Not Run chart has been revised when checking for the crank sensor 5 output voltage.

The technician is directed to read the AC voltage output of the sensor at the ignition module connector while cranking the engine. If the voltage is above a specified value, the sensor is considered OK. It has been found that a faulty sensor may still be able to generate an AC voltage higher than specified in the diagnostic chart, causing mis-diagnosis of the ignition module.

A normal sensor generates an AC voltage of approximately 1100 mV to 1300 mV. An OK but high resistance sensor that may not cause a "Cranks But Will Not Run" condition may generate a voltage as low as 500 mV - 600 mV.

An open sensor may generate an AC voltage of higher than the specified voltage in the step and cause a no start condition.

The following revisions should be made to the specified steps of Chart A-3 for the 1987-95 Service Manuals with OBD 1 diagnostic systems.