3B1-4 ELECTRICAL POWER STEERING (P/S) SYSTEM
DIAGNOSIS
The P/S system in this vehicle is controlled by P/S control module. P/S control module has an on-board diagnos-
tic system which detects a malfunction in this system.
When diagnosing troubles, be sure to have full understanding of the outline of “ON-BOARD DIAGNOSTIC SYS-
TEM” and each item in “PRECAUTION IN DIAGNOSING TROUBLE” and execute diagnosis according to “SYS-
TEM CHECK FLOW TABLE”.
ON-BOARD DIAGNOSTIC SYSTEM
P/S control module performs on-board diagnosis (self-diagnosis)
on the system and operates “EPS” warning lamp (1) (malfunction
indicator lamp) as follows.
Malfunction indicator lamp (“EPS” warning lamp) lights when
the ignition switch is turned to ON position (but the engine at
stop) regardless of the condition of P/S control system. This
is only to check the malfunction indicator lamp (“EPS” warn-
ing lamp) bulb and its circuit.
If the areas monitored by P/S control module is free from any
trouble after the engine start (while engine is running), mal-
function indicator lamp (“EPS” warning lamp) turns OFF.
When P/S control module detects a trouble which has
occurred in the areas it monitors, malfunction indicator lamp
(“EPS” warning lamp) turns ON while the engine is running
to warn the driver of such occurrence of trouble and at the
same time it stores the exact trouble area in memory inside
of P/S control module.
PRECAUTIONS IN DIAGNOSING TROUBLES
Take a note of DTC indicated first.
Be sure to read “PRECAUTIONS FOR ELECTRONIC CIRCUIT SERVICE” in Section 0A before inspection
and observe what is written there.
When two or more troubles have occurred, their DTCs are indicated 3 times each starting with the smallest
code number and up.
DTC C1122 (DTC No.22) (engine speed signal failure) is indicated when ignition switch is ON position and
engine is not running but if indication changes to a normal one when engine is started, it means nothing
abnormal.
As DTC is stored in memory of P/S control module, be sure to clear memory after repair by performing the
procedure described in “DTC CLEARANCE”.
1
ELECTRICAL POWER STEERING (P/S) SYSTEM 3B1-7
CUSTOMER QUESTIONNAIRE (EXAMPLE)
MALFUNCTION INDICATOR LAMP
(“EPS” WARNING LAMP) CHECK
1) Turn ignition switch to ON position (but without running
engine), check that malfunction indicator lamp (“EPS” warn-
ing lamp) lights up. If lamp does not light up, go to “TABLE
A”. If lamp flashes, go to “TABLE B”.
2) Start engine and check that malfunction indictor lamp
(“CHECK ENGIE” light) turns OFF.
If lamp comes OFF, P/S system is in good condition.
BRAKES 5-7
Brake warning lamp
lights after engine
startParking brake applied Release parking brake and check
that brake warning lamp turns off.
Insufficient amount of brake fluid Add brake fluid.
Brake fluid leaking from brake line Investigate leaky point, correct it
and add brake fluid.
Brake warning lamp circuit faulty Repair circuit.
Malfunctioning EBD system, if equipped with
ABS.Check system referring to Table-E
of Section 5E1.
Brake warning lamp
turns on when brake
is appliedBrake fluid leaking from brake line Investigate leaky point, correct it
and add brake fluid.
Insufficient amount of brake fluid Add brake fluid.
Brake warning lamp
fails to turn on even
when parking brake is
appliedBrake warning lamp circuit faulty Replace bulb or repair circuit.
ABS warning lamp
turns on after engine
start (If equipped)Malfunctioning ABS Check system referring to DIAG-
NOSIS of Section 5E1.
ABS warning lamp
turns on when brake
is applied (If
equipped)Malfunctioning ABS Check system referring to DIAG-
NOSIS of Section 5E1.
ABS warning lamp
does not turn on for 2
sec. after ignition
switch has turned ONBulb burnt out Replace bulb.
Malfunctioning ABS Check system referring to DIAG-
NOSIS of Section 5E1.
ABS warning lamp
flashesNew ABS hydraulic unit/control module assem-
bly installed.Perform “ABS Hydraulic Unit Oper-
ation Check”. Condition Possible Cause Correction
5-14 BRAKES
5) If rear brake pressure is not within specification, adjust it by
changing bolt (2) position as follows.
If rear brake pressure is higher than specification, move bolt
(2) center side and if it is lower, out side.
Repeat steps 3) and 4) until rear brake pressure is within
specification.
After adjustment, be sure to torque nut (1) to specification.
Tightening torque
LSPV nut (a) : 25 N·m (2.5 kg-m, 18.0 lb-ft)
6) Upon completion of fluid pressure test, bleed brake system
and perform brake test.
MASTER CYLINDER AND BRAKE FLUID
LEVEL INSPECTION
1) Check master cylinder and reservoir tank for crack, damage
and brake fluid leakage. If any faulty condition exists, correct
or replace.
2) Check that brake fluid level is between MAX and MIN marks
on reservoir tank.
2
1, (a)
NOTE:
Be sure to use particular brake fluid either as indicated
on reservoir cap of that vehicle or recommended in
owner’s manual which comes along with that vehicle.
Use of any other fluid is strictly prohibited.
Fluid level should be between MIN and MAX lines marked
on reservoir.
When brake warning lamp lights sometimes during driv-
ing, replenish fluid to MAX level.
When fluid decreases quickly, inspect brake system for
leakage. Correct leaky points and then refill to specified
level.
CAUTION:
Do not use shock absorber fluid or any other fluid which
contains mineral oil. Do not use a container which has
been used for mineral oil or a container which is wet from
water. Mineral oil will cause swelling and distortion of
rubber parts in hydraulic brake system and water mixed
into brake fluid will lower fluid boiling point. Keep all fluid
containers capped to prevent contamination.
MAX
MIN
ANTILOCK BRAKE SYSTEM (ABS) 5E-3
The main component parts of this ABS include the following parts in addition to those of the conventional brake
system.
Wheel speed sensor which senses revolution speed of each wheel and outputs its signal.
ABS warning lamp which lights to inform abnormality when system fails to operate properly.
ABS hydraulic unit/control module assembly is incorporated ABS control module, ABS hydraulic unit (actua-
tor assembly), fail-safe relay and pump motor relay.
–ABS control module which sends operation signal to ABS hydraulic unit to control fluid pressure applied to
each wheel cylinder based on signal from each wheel speed sensor so as to prevent wheel from locking.
–ABS hydraulic unit which operates according to signal from ABS control module to control fluid pressure
applied to wheel cylinder of each 4 wheels.
–Fail-safe relay (solenoid valve) relay which supplies power to solenoid valve in ABS hydraulic unit and
pump motor relay.
–Pump motor relay which supplies power to pump motor in ABS hydraulic unit.
G sensor which detects body deceleration speed. (For 4WD model only)]
This ABS is equipped with Electronic Brake force Distribution (EBD) system that controls a fluid pressure of rear
wheels to best condition, which is the same function as that of proportioning valve, by the signal from wheel sen-
sor independently of change of load due to load capacity and so on. And if the EBD system fails to operate prop-
erly, the brake warning lamp lights to inform abnormality.
[A] : RH steering vehicle shown 4. Stop lamp switch
1. ABS hydraulic unit/control module assembly 5. ABS warning lamp
2. G sensor (For 4WD vehicle only) 6. EBD warning lamp (Brake warning lamp)
3. Wheel speed sensors
156
2 4
33
[A]
NOTE:
As for the difference of RH steering vehicle and LH steering vehicle, the location of the combination
meter and the brake master cylinder assembly only changes.
ANTILOCK BRAKE SYSTEM (ABS) 5E-5
ABS HYDRAULIC UNIT/CONTROL MODULE
ASSEMBLY
ABS control module is a component of ABS hydraulic unit/control
module assembly and has the following functions.
SELF-DIAGNOSIS FUNCTION
ABS control module diagnoses conditions of the system compo-
nent parts (whether or not there is any abnormality) all the time
and indicates the results (warning of abnormality occurrence and
DTC) through the ABS warning lamp as described below.
1) When ignition switch is turned ON, ABS warning lamp lights
for 2 seconds to check its bulb and circuit.
2) When no abnormality has been detected (the system is in
good condition), ABS warning lamp turns OFF after 2 sec-
onds.
3) When an abnormality in the system is detected, ABS warn-
ing lamp lights and the area where that abnormality lies is
stored in the memory of EEPROM in ABS control module.
4) When Diag. switch terminal (2) of diagnosis connector (1)
(monitor connector) is grounded, the abnormal area is output
as DTC. It is indicated by flashing of ABS warning lamp.
(Refer to the table below.)
5) For procedure to clear all DTC’s, refer to “DIAGNOSTIC
TROUBLE CODE CLEARANCE” in this section.
Also ABS control module turns ON EBD warning lamp (brake
warning lamp) depending on the trouble that detected by the
module and EBD warning lamp does not indicate DTC as well as
ABS warning lamp.
FAIL-SAFE FUNCTION
When an abnormality occurs (an abnormal DTC is detected),
ABS control module turns OFF the fail-safe relay which supplies
power to ABS hydraulic unit. Thus, with ABS not operating,
brakes function just like the brake system of the vehicle without
ABS.
SYSTEM CONDITIONABS WARNING LAMP
Diag. switch
terminal is
not groundedDiag. switch
terminal is
grounded
In good
condition
at presentNo trouble in the past OFF DTC 12
Trouble occurred in
the pastOFF History DTC
Abnormal-
ity exists
at presentNo trouble in the past ON Current DTC
Trouble occurred in
the pastONCurrent and
history DTCs
3. Ground terminal
4. Service wire
3 11
2
4
6-46 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE A-1 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK - LAMP DOES
NOT COME “ON” AT IGNITION SWITCH ON (BUT ENGINE AT STOP)
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then,
ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine
starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected,
MIL remains ON even when the engine is running.
INSPECTION
1. BATT fuse 3. IG METER fuse 5. Monitor connector 7. To ignition switch
2. Main fuse box 4. To battery 6. MIL
[A] : Case of TYPE A is shown
(See NOTE)[B] : Case of TYPE B is shown
(See NOTE)
1
12V5V
ECM
23
+BB
DA
C
BLK/WHT
BRN/WHT
BLK/RED
BLK/RED
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
BLK
DN
TS
GNDMON
PPL/WHTC42-27 [A]
C42-16 [A]
PNK/BLUC42-28 [A]
7 4
G02-1 [A]IG1
5
6IG1
WHT/GRN
BLK/WHT
G02-6 [A]
C41-5 C41-6 C41-10 C41-11 [B]C41-14 [B]
C41-15 [B]
C41-8 [B]
G02-9 [B]
PPL/WHT
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 MIL Power Supply Check
1) Turn ignition switch ON.
Do other indicator/warning lights in combination
meter comes ON?Go to Step 2.“IG METER” fuse blown,
main fuse blown, ignition
switch malfunction, “BLK/
WHT” circuit between “IG
METER” fuse and combi-
nation meter or poor cou-
pler connection at
combination meter.
2 ECM Power and Ground Circuit Check
Does engine start?Go to Step 3. Go to TABLE A-5 ECM
POWER AND GROUND
CIRCUIT CHECK.
If engine is not cranked,
go to DIAGNOSIS in Sec-
tion 6G.
CHARGING SYSTEM 6H-9
ON-VEHICLE SERVICE
BATTERY
JUMP STARTING IN CASE OF EMERGENCY
WITH AUXILIARY (BOOSTER) BATTERY
Both booster and discharged battery should be treated carefully when using jumper cables. Follow procedure
outlined below, being careful not to cause sparks.
1) Set parking brake and place automatic transmission in PARK (NEUTRAL on manual transmission). Turn off
ignition, turn off lights and all other electrical loads.
2) Check electrolyte level. If it is below low level line, add distilled water.
3) Attach end of one jumper cable to positive terminal of booster battery and the other end of the same cable to
positive terminal of discharged battery. (Use 12-volt battery only to jump start engine).
4) Attach one end of the remaining negative cable to negative terminal of booster battery, and the other end to
a solid engine ground (such as exhaust manifold) at least 45 cm (18 in.) away from battery of vehicle being
started.
5) Start engine of vehicle with booster battery and turn off electrical accessories. Then Start engine of the vehi-
cle with discharged battery.
6) Disconnect jumper cables in the exact reverse order.
WITH CHARGING EQUIPMENT
CAUTION:
If vehicle is manual transmission model and has a catalytic converter, do not push or tow it to start.
Damage to its emission system and/or to other parts may result.
WARNING:
Departure from these conditions or procedure described below could result in:
–Serious personal injury (particularly to eyes) or property damage from such causes as battery
explosion, battery acid, or electrical burns.
–Damage to electronic components of either vehicle.
Remove rings, watches, and other jewelry. Wear approved eye protection.
Be careful so that metal tools or jumper cables do not contact positive battery terminal (or metal in
contact with it) and any other metal on vehicle, because a short circuit could occur.
WARNING:
Do not connect negative cable directly to negative terminal of dead battery.
CAUTION:
When jump starting engine with charging equipment, be sure equipment used is 12-volt and negative
ground. Do not use 24-volt charging equipment. Using such equipment can cause serious damage to
electrical system or electronic parts.