System Tests: Notes

CAUTION: When battery is disconnected or modules are replaced, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

NOTE: Before beginning system tests, perform TROUBLE SHOOTING .

SYMPTOM INDEX

Symptom

Perform Test

Fuel Gauge Inaccurate

Voltmeter Inaccurate

Oil Pressure Gauge Inaccurate

Temperature Gauge Inaccurate

Temperature Warning Light Flickers & Gauge Reads Fully Hot

Speedometer Inoperative But Odometer Functions Properly

⁽¹⁾

Trip Odometer Inoperative, Speedometer Okay

⁽²⁾

Seat Belt Warning Indicator Inoperative

Speedometer Reading Inaccurate

Speedometer/Odometer Inoperative

Brake Warning Indicator Inoperative

Charge Warning Indicator Inoperative

Anti-Lock Brake Warning Indicator Inoperative

CHECK ENGINE Light (MIL) Inoperative

High Beam Indicator Inoperative

Left Turn Indicator Inoperative

Right Turn Indicator Inoperative

Air Bag Warning Imperative

Low Oil Pressure/High Coolant Temperature Warning Indicator Inoperative

Brake Warning Indicator Always On

⁽³⁾

No Communication With Natural Gas Vehicle Module

Integrated Circuit Display Inoperative Or Inaccurate

Fuel Gauge Inaccurate (NGV)

⁽⁴⁾

⁽¹⁾	Replace instrument cluster.

⁽²⁾	Ensure trip lever is not binding, repair as necessary. If trip lever is okay, replace instrument cluster.

⁽³⁾	See appropriate article in BRAKES.

⁽⁴⁾	Using NGS tester, perform NGV module self-test. If any DTCs exist, perform appropriate test in accordance with DTC retrieved. See NATURAL GAS VEHICLE MODULE DTC INDEX table under SELF-DIAGNOSTIC SYSTEM. If no DTCs exist, perform TEST AI: ECU CIRCUIT FAILURE.