Specifications

39
Data Parameters Engine Parameters
AIR LOGIC CHAIN
Range: __________________________________________________________ YES/NO
Used on DM2 systems. This parameter indicates whether the onboard diagnostic secondary air
system tests have run (YES) or not run (NO).
AIR MASS
Range: ________________________________________ 0 to 500 kg/h or 0 to 500 mg/S
Used on DM2, EDS, ERE/EVE/ASF (IFI Diesel)), HFM, ME10, ME20 and SIM4 systems. The
ECU generates this parameter based on the input signal from the mass airflow sensor. The
reading indicates the mass of the intake air charge in kilograms per hour (kg/h), or milligrams per
stroke (mg/S). Values on a warmed-up vehicle vary by system and by engine.
AIR PUMP
Range: _________________________________________________ YES/NO or ON/OFF
Used on DM, DM2, HFM, LH, ME10 and ME20 systems. This parameter indicates the state of
the secondary air pump. The display reads YES or ON when the pump is activated, and reads
NO or OFF when the pump is off. Secondary air is pumped into exhaust system to reduce
emissions under certain operating conditions. On HFM systems the pump should be on (YES)
when engine temperature is below 40°F (4°C).
AIR PUMP ACTIVATION
Range: __________________________________________________________ YES/NO
Used on DM2 systems. This parameter indicates whether the ECU has commanded the air
pump to activate.
AIR PUMP SWITCHOVER VALVE
AIR PUMP SWITCHOVER VALVE, LEFT
AIR PUMP SWITCHOVER VALVE, RIGHT
Range: ____________________________________________________ OPEN/CLOSED
Used on ME27, ME28 and SIM4 systems. These discrete parameters indicate whether the air
pump switch-over solenoid valves are open or closed. At cold start and during warm-up, solenoid
valve should be in OPEN or up position, which directs air pump flow into the exhaust manifold to
help reduce emissions. With the engine fully warmed up, the solenoid valve should read
CLOSED, shutting or closing the air pump chamber to the exhaust manifold.
The SIM4 system does not have an air pump, but instead uses the supercharger as an air-pump
during warm-up. The Recirculating Air Flap actuator is used to direct air into exhaust manifold
and also is used to generate an Air Pump Switchover Valve position status.
Table 5-1 Typical idle readings
System Engine Typical Idle Reading
HFM
4-cylinder 8–15 kg/h
6-cylinder 13–22 kg/h
8-cylinder 15–25 kg/h
12-cylinder 12–22 kg/h
ME10 & ME20
4-cylinder 8–15 kg/h
6-cylinder 10–20 kg/h
8-cylinder 12–25 kg/h
12-cylinder 10–20 kg/h
SIM4 — 10–20 kg/h