12v.org

Home The Engine The Cars Links Registry FAQ Maintenance Modifications
 
Features   |   Identification   |   Component Locations   |   How it Works


MMS-3xx Functional Wiring Diagram

Components


F60: Idle switch
G4: Crankshaft Position Sensor
G6: Fuel pump
G28: Engine Speed Sensor
G39: Oxygen sensor I
G40: Hall Sensor
G61: Knock sensor I
G62: Engine Coolant Temperature (ECT) sensor
G66: Knock sensor II
G69: Throttle valve potentiometer
G70: Mass Air Flow (MAF) sensor
G98: Exhaust Gas Recirculation (EGR) temperature sensor
G108: Oxygen sensor II
J176: Fuel pump relay
J192: Engine Control Module (ECM)
N: Ignition coil for cylinders 1 and 6
N18: EGR frequency valve
N30: Fuel injector, cylinder 1
N31: Fuel injector, cylinder 2
N32: Fuel injector, cylinder 3
N33: Fuel injector, cylinder 4
N71: Idle Air Control (IAC) valve
N80: EVAP carbon canister frequency valve
N83: Fuel injector, cylinder 5
N84: Fuel injector, cylinder 6
N122: Power stage for ignition coils
N128: Ignition coil for cylinders 2 and 4
N156: Intake manifold change-over valve
N158: Ignition coil for cylinders 3 and 5
P: Spark plug connector (6x)
Q: Spark plug (6x)
S17: Fuse for G6
S19: Fuse for diagnostic connector
S64: Circuit breaker for N158, N128, and N
S72: Circuit breaker for N30, N31, N32, N33, N83, and N84
S73: Circuit breaker for G39, G108, N18, N80, and N156
S74: Circuit breaker for G70 and G74

Additional Signals


B8: Throttle valve signal (not pictured)
B9: Road speed signal (not pictured)
B10: Engine speed signal (not pictured)
B11: Fuel consumption signal (not pictured)
B12: Shift lever position signal (not pictured)
B13: Shift point signal (not pictured)
C10: A/C compressor signal (not pictured)
C12: Diagnostic signal for Rapid Data (K circuit)
C13: Diagnostic signal for Rapid Data (L circuit)
C14: Flash code signal 		 
Mass Air Flow Sensor G70
G70
A hot wire air mass sensor is used to measure the air flow into the engine. The air mass sensor is attached to the air filter housing. The sensor housing includes a baffle which reduces air turbulence and pulses. The air sensor has no moving parts.

The voltage signal from the air mass sensor is proportional to the air flow to the intake manifold. The signal is used to calculate all controls that depend on engine load, such as injection quantity, ignition timing, exhaust gas recirculation, and fuel tank ventilation.

The mass air flow sensor has changed from previous MPI versions. Because of the fully adaptive oxygen sensor control, the CO adjustment potentiometer has been eliminated. The sensor housing is now a signle casting with the air bypass positioned in the center of the housing.

The characteristic curve of this sensor is different than the previous design. It must not be installed on the earlier version of the MPI system.

Substitute Function

If a fault develops with the signal from the air mass sensor, the signal from the throttle potentiometer is used as a substitute in order for the car to remain driveable.

Self-diagnosis

The ECU recognizes two fault conditions of the air mass sensor:
  • An open circuit
  • A short circuit
 
 
 
Disclaimer
 
Back  
Home
Top