12v Pages - The Engine - MMS300

Features | Identification | Component Locations | How it Works

MMS-3xx Functional Wiring Diagram

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

Knock Sensors I and II G61 and G66

G61, G66

Two knock sensors are used. The use of two sensors makes it possible for the system to 'hear' better and be more sensitive.

When engine knocking occurs, the ignition timing is retarted until knocking is eliminated. Since engine knock limit varies from cylinder to cylinder, knock regulation is done cylinder selectively.

Knock sensor I is located on the right cylinder bank, under the intake manifold, and monitors cylinders 1, 2, and 3.

Knock sensor II is located on the left cylinder bank and monitors cylinders 4, 5, and 6.

Knock sensor control starts when the coolant temperature is 104°F (40°C) or above.

The ignition angle of the knocking cylinder is retarded in steps to a maximum of 12° or until the knocking stops.

If the cylinder knock continues, the ECU will switch from the premium fuel ignition map to the ignition map for regular fuel. This allows the ignition timing to be retarded up to three additional degrees.

G61, G66

Substitute Function

If the MPI control unit does not receive a signal from a knock sensor, the ignition timing for the relevant cylinders is retarded to the maximum amount of twelve degrees.

Self-diagnosis

The ECU recognizes an open circuit if a signal is not received from a knock sensor, the coolant temperature is 104°F (40°C) or above, and the engine speed is 3500 rpm or above.