L1 Inputs: Sensors Operation & Info

APP1 & APP2

Potentiometers

APP1: .5v (Pedal Released) - 3.5v (WOT)

APP2: 1.5v (Pedal Released) - 4.5v (WOT)

ECM Interpretation

• APP signal greater than 80% = WOT

• Failure of one = max to throttle to 35%

• Failure of both or correlation error = disable the TAC, auto return to 15%

A/C Pressure Sensor

Three-wire solid-state

.25 volts = 25 psi

4.5 volts = 450 psi

Compressor disabled below 40 psi or above 420 psi

Air/Fuel Ratio Sensors

Planar-type sensor
ARFS 1/1 on bank 1 exhaust manifold, ARFS2/1 on bank 2

14.7 AFR = 2.5 volts

20:1 AFR = 4.3 volts

11:1 AFR = 1.3 volts

ECM PWM sensor to control temp

• Lean = + 3000 micro amps to push out oxygen

• Rich = - 2000 micro amps to pull in oxygen

• Typical ohms = 2-6 at 20 C

Camshaft Position Sensor

Hall effect

loss of signal fully retard position, no overlap
if no CMP during cranking, ECM turns off injectors

Crankshaft Postion Sensor

Magnetic-type 35 pulses each revolution

missing tooth 60 degrees before TDC cyl 1

EGR Position Sensor

three-wire non-adjustable potentiometer

.5v = closed

4.5v= open

Fuel Level Sensor

potentiometer

.5v-4.5v, 0-100% full

Fuel Pressure Sensor

5 wire solid state sensor

Located on fuel rail

.5v - 4.5 v, 0-90 psi
3,2 v at 60 psi

referenced to atmospheric pressure

Fuel Tank Pressure Sensor

.5v = -.5 psi, 4.5v = .5 psi
Located on fuel rail

Senses vapor pressure in EVAP system compared to atmospheric pressure

Knock Sensor

Two-wire piezoelectric sensor that generate an AV voltage spike when engine vibrates within specified frequency range

ECM retard ignition

normally 2.5 volts DC

Heated Oxygen Sensor

Electrically heated zirconia sensors
Mounted after front catalytic converter

0 - 1v
Low voltage = more oxygen, Lean

High voltage = less oxygen, Rich

B+ to heaters with ignition on
ECM will provide ground for heaters after 2 min of engine opp
typically 8-12 ohms at 20 C (68 F)

Manifold Absolute Pressure Sensor

Located on the intake manifold

4.5 volt = 0 inHg
.5 volt = 24 inHg
Sea level at idle 20 inHg = 1.17 v

updates BARO measurement at WOT

Mass Airflow Sensor

Hot-wire design that senses airflow into the intake manifold

.2v = 0 gm/sec
4.8 volts = 175 gm/sec

Sea level no-load idle reading is .85v ~3 gm/sec

Throttle Position Sensors

Pair of redundant non-adjustable potentiometers that senses throttle position

TP1 4.5 volt at closed, .5 at WOT
TP2 .5 volt at closed, 4.5 at WOT

Failure of one will set DTC and limit the max throttle to 35%
Both failure will set DTC and disable TAC (Throttle Actuator Control)

When Disabled spring-loaded throttle plate returns to default 15% position (fast Idle)

Engine Coolant Temp

NTC

-40 F —> 248 F

At 212 F = .46 v

Fuel Temp Sensor

Five wire combined solid state NTC sensor
On fuel rail

Measures temp from -40 F to 248 F
At 86 F 2.6 volt

Helps command FPCM

Intake Air Temp Sensor

NTC

at 86 F 2.6 volt

Trans Fluid Temp

Signal Used by TCM to delay shifting when fluid cold and TCC when fluid is hot

Transmission Range Switch

Indicates what gear

Used by TCM to control line pressure, upshifting, downshifting

Transmission turbine shaft speed

Magnetic Type on input shaft
TCM uses to control TCC operation and sense transmission slippage

Variable Valve Lift System

Two, three-wire, non-adjustable potentiometers that sense the variable valve lift motor shaft position for each variable valve lift motor

Will read .5 valve at low lift (0% command) and 4.5 volt at high lift (100% command)

At idle is base lift, at WOT maximum lift

VSS

magnetic type on final drive

TCM uses to control upshifts, downshifts, TCC
sends data to ECM to control high speed fuel cutoff, and to I/C for speedometer