1998 HONDA CIVIC rolling

PGM-FI System
System Description (cont'dl
Lean Burn Control {D16Y5 engine: CvT)
The lean burn control system is based on the characteristic increase in crankshaft angular acceleration which occurs inwhen the air-fuel ratio gets leaner.
The CKF sensor, which is mounted on the crankshaft, monitors sngine speed, lf crankshaft angular acceleration falls belowa certain level (target air-fuel ratio level), the amount of injected fuel is reouceo.
lf crankshaft angular acceleration exceeds this level. the amount of fuel is increased.
This system improves fuel economy and driveability by controlling the amount of injected fuel in the lean burn rangeimmediatelv before combustion starts to deteriorate.
1 1-1 06
TOC/CKP/CYP SENSOR
MAP SENSOR
CKF SENSOR
ECM
Comparison oI current airfuel ratio to target ratio

Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1l
The scan tool indicates Diagnostic Trouble Code (DTC) P0133: A slow response problem in the Primary Heated
Oxygen Sensor {Primary H02S) (Sensor 1) circuit.
The scan tool indicates Diagnostic Trouble code (DTC) Pl163: A slow response problem in the Primary Heated
Oxygen Sensor (Primary HO2S) (Sensor 1)circuit
Description
By controlling the airlfuel ratio with a Primary Ho2S {Sensor 1) and a secondary HO2S {Sensor 2), the deterioration of the
primary HO2S (Sensor 1) can be evaluated by its feedback period. when the feedback period of the Ho2s exceeds a cer-
tain value during stable driving conditions, the sensor will be judged as deteriorated
when deterioration has been detected during two consecutive trips. the MIL comes on and DTC P0133 or P1163* will be stored'
NOTE: tf DTC P0131, P0132 and/or P0135 are stored at the same time as DTC P0133, troubleshoot those DTCS first' then
troubleshoot DTC P0133. lf DTC Pl 162, P1168 and/or P1169 are stored at the same time as DTC P1163, troubleshoot those
DTCS first, then recheck for DTC Pl163.
Possible Cause
o Primary HO2S (Sensor 'l) Deterioration
o Primary HO2S Heater (Sensor 1)Deterioration
. Exhaust system leakage
Troublsshooting Flowchart
tFol3al
I P1163
- The MIL has been reported on- DTC P0133 and/or Pl163* is
stored,
Problem Verilication:1. Do the ECM/PCM Reset Pro
cedure-2. Connect the scan tool
3. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
4. Connect the SCS service con-
nector.5. Test-drive u nder Iollowing
conditions.- 55 mph (88 km/h) steadyspeed- A/f in D position {M/T in
5th gear)
Until readiness code comes
lntermittent failure, 3Y3tem i3 OK
at thi3 time. Ch.ck lol Poor con-
ncctions or loosc wiros at C123
{C145)! lPrimary HO2S, Sensor 1l
and ECM/PCM.
Replace th6 Prim.ry HO2S (Sen'
sor 11.
*: P'l163 (D16Y5 engine with M/T)
11-145

GRADE LOGIC CONTROL SYSTEM
How it works:
The pCM compares actual driving conditions with driving conditions memorized in the PCM, based on the input from the
vehicle speed sensor, the throttle position sensor, the barometoric pressure sensor, the engine coolant temperature sensor,
the brake switch signal, and the shift lever position signal, to control shifting while a vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS OETECTED
O.iving Resi3lence
Judgemenl ot Conirolling Arca
. Ascending mod€
lFuzzy loqicl. Gradual Ascending mode' Ste€p Ascending mode. Oescending mode. Gr.du.l Descending mode. Steep D6cending mode
14-15

t
To STEERING GEARBOX
To STEERING GEAREOx
@ The fluid volume that flows thorough oil passage A
and the pressure djfference applied to the sub-valve
increase in proportion to the engine speed. The
sub-valve lowers overcoming the spring force, and
it stans to close the variable orifice to regulate the
discharge volume, When this happens, the fluid vol-
ume flowing to the steering gearbox decreases as
the engine speed increases. At the same time, the
flow control valve continues to control the fluid vol-
ume to the return Port,
@ As the engine speed increases funher, the pressure
difference at the sub-valve increases further as well.
The sub-valve then closes the variable orifice com-
pletely, regulating the discharge volume further.
When this happens, the fluid volume discharged
from the pump to the steering gearbox is regulated
and maintained at a given level until the engine
speed reaches the high speed range The flow con-
trol valve functions continues to control the fluid
volume to the return Port.
Pressure Relief
Pressure at the discharge side of the fixed orifice is
directed to the bottom of the flow control valve. When
the pressure builds up, the relief valve in the flow con-
trol valve opens to release the pressure at the bottom of
the valve. This allows the flow control valve to be
pushed back by the pressure difference, and the fluid
volume to the pump return port increases.
As explained above. the system keeps the pump dis-
charge pressure (relief pressure) from exceeding the
given level by controlling the volume of the fluid to the
pump relurn pon,
1.,DAMPING ORIFICE{Docreases excessiv€vibration in the valv6.)
17-19
)
RELIEF VALVE {Opan)
SUB.VALVE
FLOW CONTROL VALVE
/F ft>..\
'-€/K\A/A
o'.'to"5lo'#2"n af11\D7
FLOW CONTROL VALVE