Retrieving Codes

Ensure ignition switch is in the OFF position. Using a jumper wire, connect ground and diagnostic terminals of Assembly Line Diagnostic Link (ALDL) White connector. See Fig 1 . Connector is located behind right kick panel in passenger compartment. Turn ignition switch to ON position. Read fault code(s). Proceed to appropriate charts under DIAGNOSTIC CODE CHARTS to diagnose fault codes.
WARNING: Ensure jumper wire is connected to ALDL White connector. A connector for Supplemental Inflatable Restraint (SIR) system is located next to ALDL connector.
If no fault codes are stored, CHECK ENGINE light will flash on and off rapidly until jumper wire is disconnected. Count the number of flashes and look for pauses in flashing to ensure no fault codes are overlooked. If fault codes are stored, code will flash 3 times starting with the lowest code.

Fig 1: Identifying ALDL White Connector Terminals (Storm)

Courtesy of GENERAL MOTORS CORP.

FAULT CODE IDENTIFICATION (STORM)

Code	Circuit Affected	Probable Cause
13	Oxygen Sensor	Open Circuit
14	Coolant Temp. Sensor	High Temp. Indicated
14	Coolant Temp. Sensor	Low Temp. Indicated
21	Throttle Position Sensor	Signal Voltage High
21	Throttle Position Sensor	Signal Voltage Low
23	Intake Air Temp. Sensor	Low Temp. Indicated
23	Intake Air Temp. Sensor	High Temp. Indicated
24	Vehicle Speed Sensor	Incorrect Signal Voltage
32	EGR System	EGR Failure
33	MAP Sensor	Signal Voltage High, Low Vacuum
33	MAP Sensor	Signal Voltage Low, High Vacuum
42	Electronic Spark Timing	Open/Short Circuit
44	Oxygen Sensor	Lean Exhaust Indicated
45	Oxygen Sensor	Rich Exhaust Indicated
51	ECM Failure	ECM Failed Or PROM Failure