Specifications

Data Parameters Engine Parameters

INTAKE AIR TEMPERATURE(°)

Range: _________________________________________ –40 to 199°C or –40 to 389°F

These ECM-calculated parameters indicate the intake air temperature based on the Intake Air

Temperature (IAT) sensor signal voltage.

INTAKE AIR TEMPERATURE(V)

Range: _________________________________________________________ 0 to 12.0V

This parameter displays the intake air temperature (IAT) sensor voltage. The sensor has a

negative temperature coefficient; as temperature rises, voltage decreases.

On mass airflow (MAF) systems, the IAT sensor may be mounted inside the mass airflow sensor,

in the intake manifold, or inside the air cleaner. The ECM uses the IAT sensor to calculate

ignition timing.

On airflow meter systems, the IAT sensor is mounted inside the airflow meter in front of the

measuring flap. The ECM uses this IAT sensor to help calculate intake air density.

KNOCK(V)

KNOCK 1 (KNOCK SENSOR 1)(V)

KNOCK 2 (KNOCK SENSOR 2)(V)

Range: ________________________________________________________ 0 to 5.00 V

These parameters indicate the signal received by the ECM from the knock sensor or sensors.

Knock sensors only generate a signal when detonation is detected. The higher the signal

voltage, the greater the amount of detonation.

KNOCK CONTROL

Range: __________________________________________________________ ON/OFF

This ECM-commanded parameter indicates the status of knock control. Reads ON when the

ECM is detecting detonation or misfiring and is retarding the ignition timing to compensate.

MIL LAMP (MALFUNCTION INDICATOR LAMP)

Range: __________________________________________________________ ON/OFF

This ECM-commanded parameter indicates the status of the malfunction indicator lamp (MIL).

Reads ON when the ECM is commanding the lamp to light.

MIXTURE

Range: _______________________________________________________ RICH/LEAN

This parameter indicates whether the engine is running a rich or lean air/fuel ratio. The

parameter reads RICH or LEAN based on the voltage output from the oxygen sensor (O2S)

mounted in the exhaust stream. The amount of oxygen in the exhaust stream is directly related

to the oxygen content in the intake air/fuel mixture. Before beginning to vary the air/fuel ratio

based on O2S signals, the ECM must be in closed-loop operation and the O2S must be at

operating temperature.

MSR INTERVENT (MSR INTERVENTION)

Range: __________________________________________________________ ON/OFF

This parameter indicates whether the engine drag torque control (MSR) system is on. The MSR

system works in conjunction with the Dynamic Stability Control (DSC) system (see page 31) and

other systems to help the driver maintain control during certain hazardous driving conditions.

While decelerating in a high gear and on a slippery road surface, the engine control module

(DME) may cut off fuel. This could cause the drive wheels to drag and loose traction, causing the

vehicle to become unstable. To prevent this, the MSR system opens the idle control valve and

cancels deceleration fuel cutoff. This action accelerates the engine slightly, reducing wheel drag

and increasing vehicle stability.