Specifications

Data Parameters Engine Parameters

O2 SENSOR, DOWNSTREAM CAT, CYL 1-3; 4-6; 7-9; 10-12

O2 SENSOR, DOWNSTREAM CAT

O2 SENSOR, DOWNSTREAM CAT, LEFT

O2 SENSOR, DOWNSTREAM CAT, RIGHT

O2 SENSOR, UPSTREAM CAT, CYL 1-3; 4-6; 7-9; 10-12

O2 SENSOR, UPSTREAM CAT

O2 SENSOR, UPSTREAM CAT, LEFT

O2 SENSOR, UPSTREAM CAT, RIGHT

Range: ________________________________________________________ 0 to 2.00 V

Used on ME27 and ME28 systems. The terms “1-3,” “4-6,” “7-9,” and “10-12” refer to four

separate groups of parameters. The oxygen sensor (O2S) is the primary sensor that indicates

whether the engine is running rich or lean. O2Ss have a range of 0.0 to 1.2 volts (V). A high 0.48

to 1.00 V signal indicates a rich mixture; a low signal indicates a lean mixture. Normally, the O2S

voltage ranges from 0.1 to 1.0 V. The O2S must be hot, and the ECU must be in closed loop

before the ECU will respond to the sensor signal. On some applications, individual cylinder sets

of O2S readings are useful for determining specific cylinder fuel mixture and misfire diagnosis.

O2S (LAMBDA) CONTROL

Range: ________________________________________________________ –10 to 10%

Used on DM, HFM and LH systems. This parameter is the short-term fuel metering correction

based on O2S input. Lambda control determines the injection time in order to maintain a

stoichiometric (14.7:1), or 1.0 Lambda, air-fuel ratio. Zero is the base setting, no correction.

Positive readings indicate increased injector duration to correct a lean condition, and negative

readings indicate reduced time to correct a rich condition.

O2S (LAMBDA) CONTROL APPROVED

Range: __________________________________________________________ YES/NO

Used on DM2 systems. This parameter shows whether the system is in closed loop, and if the

ECU is responding to oxygen sensor (O2S) feedback signals. The display reads YES in closed

loop and NO in open loop.

O2S (LAMBDA) CONTROL AFTER TWC

O2S (LAMBDA)CTRL AFT. TWC LEFT

O2S (LAMBDA)CTRL AFT.TWC RIGHT

Range: ______________________________________________________ not available

Used on ME10 and ME20 systems. These parameters are the outputs in milliseconds of lambda

control based on the downstream oxygen sensor (O2S) signals. No operation or range

information is available at this time.

O2S (LAMBDA) CONTROL BEFORE TWC

O2S (LAMBDA) CTRL BEF. TWC RIGHT

O2S (LAMBDA) CTRL BEFORE TWC LEFT

O2S CONTROL, UPSTREAM CAT(%)

Range: ________________________________________________________ –25 to 25%

Used on ME10 and ME20 and SIM4 systems. These parameters represent the short-term fuel

metering correction required to maintain a stoichiometric (14.7:1), or 1.0 Lambda, air-fuel ratio.

Fuel corrections are based on the indicated O2S signals. Zero is the base setting, no correction.

Positive readings indicate increased injector duration to correct a lean condition, and negative

readings indicate reduced on time to correct a rich condition.