Glossary of Terms

ABS Antilock Brake System

Backfire, Popback Fuel ignites in either the intake or the exhaust system

CKP Crankshaft Position Sensor

CMP Camshaft Position Sensor

Cuts Out, Misses A steady pulsation or the inability of the engine to maintain a consistent rpm.

DLC Data Link Connector (previously called engine diagnostic connector)

Detonation, Spark Knock A mild to severe ping, especially under loaded engine conditions.

ECT Engine Coolant Temperature Sensor

EGR Exhaust Gas Recirculation Valve And System

Generator Previously called alternator

Hard Start The engine takes longer than usual to start, even though it is able to crank normally.

Hesitation, Sag, Stumble There is a momentary lack of response when the throttle is opened. This can occur at all vehicle speeds. If it is severe enough, the engine may stall.

IAC Idle Air Control Motor

IAT Intake/Inlet Air Temperature Sensor

JTEC Jeep/Truck Engine Controller

Lack of Power, Sluggish The engine has less than expected power, with little or no increase in vehicle speed when the throttle is opened.

LDP Leak Detection Pump

MAP Manifold Absolute Pressure Sensor

MIL Malfunction Indicator Lamp

MTV Manifold Tuning Valve

NGC Next Generation Controller

O2S Oxygen Sensor

PCI Programmable Communication Interface

PCM Powertrain Control Module

PCV Positive Crankcase Ventilation

PEP Peripheral Expansion Port

Poor Fuel Economy There is significantly less fuel mileage than other vehicles of the same design and configuration.

Rough, Unstable, or
Erratic Idle/Stalling The engine runs unevenly at idle and causes the engine to shake if it is severe enough. The engine idle rpm may vary (called hunting). This condition may cause stalling if it is severe enough.

SBEC Single Board Engine Controller

SKIM Sentry Key Immobilizer Module

SKIS Sentry Key Immobilizer System

Start & Stall The engine starts but immediately dies.

Surge Engine rpm fluctuation without corresponding change in Throttle Position Sensor.

TPS Throttle Position Sensor

TRS Transmission Range Sensor

VSS Vehicle Speed Sensor/Signal