sensor TOYOTA TERCEL 1996 Service Repair Manual

BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
+V
-VHigh Speed
Low Speed
CoilNS
0 DI-128
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
DTC 31, 32, 33, 34 Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
the ABS system. The front and rear rotors each have 48 serra-
tions.
When the rotors rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotors, the frequency is used by the ECU
to detect the speed of each wheel.

DTC No.DTC Detecting ConditionTrouble Area
31, 32, 33, 34
Detection of any of conditions 1 through 3:
1. At vehicle speed of 10 km/h (6 mph) or more, pulses are
not input for 5 sec.
2. Momentary interruption of the speed sensor signal oc-
curs at least 7 times in the time between switching the
ignition switch ON and switching it OFF
3. Abnormal fluctuation of speed sensor signals with the
vehicle speed 20 km/h (12 mph) or more

Right front, left front, right rear or left rear speed sensor

Open or short in each speed sensor circuit

ECU
HINT:

DTC 31 is for the right front speed sensor.

DTC 32 is for the left front speed sensor.

DTC 33 is for the right rear speed sensor.

DTC 34 is for the left rear speed sensor.
Fail safe function:
If trouble occurs in the speed sensor circuit, the ECU cuts off current to the ABS control (solenoid) relay and
prohibits ABS control.
DI983-01

R12890F15193
Right Front Speed Sensor
Left Front Speed Sensor
Right Rear Speed Sensor
Left Rear Speed Sensor2
1 2
2 2
1 1 1W B
R
G
9 10
A12FR+
FR-
FL+
FL-
RR+
RR-
RL+
RL- FSS
3 229
8 BRA12
A12
A12
A12
A13
A13
A13
A13
2 21
23ABS ECU
5 V
LG L
V
P
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-129
1996 TERCEL (RM440U)
WIRING DIAGRAM

R14676
21
R14669
1 2
DI-130
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check speed sensor.
Front:
PREPARATION:
Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 0.6 - 2.5 kW
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MW or higher
Rear:
PREPARATION:
Disconnect the speed sensor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector.
OK:
Resistance: 0.8 - 1.8 kW
CHECK:
Measure the resistance between terminals 1 and 2 of the speed
sensor connector and body ground.
OK:
Resistance: 1 MW or higher
NG Replace speed sensor.
NOTICE:
Check the speed sensor signal last (See page DI-1 11).
OK
2 Check for open and short in harness and connector between each speed sensor
and ECU (See page IN-26).
NG Repair or replace harness or connector.
OK

R00948
BR4248
BR3795
OK NG
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-131
1996 TERCEL (RM440U)
3 Check sensor rotor and sensor installation.
Front:
PREPARATION:
Remove the drive shaft (See page SA-18).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches or missing teeth.
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
CHECK:
Check the front speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and steering
knuckle.
Rear:
PREPARATION:
Remove the drum (See page SA-39).
CHECK:
Check the sensor rotor serrations.
OK:
No scratches or missing teeth.
CHECK:
Check the sensor tip.
OK:
No scratches or foreign objects on the sensor tip.
CHECK:
Check the rear speed sensor installation.
OK:
The installation bolt is tightened properly and there is
no clearance between the sensor and rear axle carri-
er.
NG Replace speed sensor or rotor.
NOTICE:
Check the speed sensor signal last (See page DI-1 11).
OK
Check and replace ABS ECU.

F00414
24ABS ECU
AA123DLC1
Ts
16
EC
E1TsL
B-RAEA13
B-RL12 V
J/C
J1
R13006
E1
DLC1
Tc
- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-143
1996 TERCEL (RM440U)
Ts Terminal Circuit
CIRCUIT DESCRIPTION
The sensor check circuit detects abnormalities in the speed sensor signal which cannot be detected with
the DTC check.
Connecting terminals Ts and E
1 of the DLC1 in the engine compartment starts the check.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals Ts and E1 of DLC1.
CHECK:
(a) Turn the ignition switch ON.
(b) Measure the voltage between terminals Ts and E
1 of the
DLC1.
OK:
Voltage: 10 - 14 V
OK If ABS warning light does not blink even after Ts
and E
1 are connected, ECU may be defective.
NG
DI4M1-02

N12151
DI95N-01
R13006
E1
Tc
AT0716
Normal Code
ON
OFF0.25
0.25
DI-148
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
PRE-CHECK
1. SRS WARNING LIGHT CHECK
(a) Turn the ignition switch to ACC or ON and check that the
SRS warning light lights up.
(b) Check that the SRS warning light goes out after approx.
6 seconds.
HINT:

When the ignition switch is at ACC or ON and the SRS
warning light remains on or flashes, the airbag sensor as-
sembly has detected a malfunction code.

If, after approx. 6 seconds have elapsed, the SRS warn-
ing light sometimes lights up or the SRS warning light
lights up even when the ignition switch is OFF, a short in
the SRS warning light circuit can be considered likely.
Proceed to ºSRS warning light system malfunctionº on
page DI-180, DI-182.
2. DTC CHECK (Using diagnosis check wire)
(a) Output the DTC.
(1) Turn the ignition switch to the ACC or ON position
and wait approx. 20 seconds.
(2) Using SST, connect terminals Tc and E1 of the
DLC1.
SST 09843-18020
NOTICE:
Never make a mistake with the terminal connection posi-
tion as this will cause a malfunction.
(b) Read the DTC.
Read the 2-digit DTC as indicated by the number of times
the SRS warning light blinks. As an example, the blinking
patterns, normal, 11 and 31 are as shown on the illustra-
tion.

Normal code indication.
The light will blink 2 times per second.

Malfunction code indication.
The first blinking output indicates the first digit
of a 2-digit DTC. After a 1.5 second pause,
the second blinking output will indicate the
second digit.

DI4M7-02
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-151
1996 TERCEL (RM440U)
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the DTC check, check the circuit listed for that code in the table
below (Proceed to the page given for that circuit.).
DTC No.
(See Page)Detection ItemTrouble AreaSRS
Warning Light
Nl
System normal-OFFNormal
(DI-177)
Source Voltage drop
Battery

Airbag sensor assemblyON
11
(DI-155)

Short in squib circuit (to ground)
Steering wheel pad (D squib)

Front passenger airbag assembly (P squib)

Spiral cable

Airbag sensor assembly

Wire harness
ON
12
(DI-162)

Short in squib circuit (to B+)
Steering wheel pad (D squib)

Front passenger airbag assembly (P squib)

Spiral cable

Airbag sensor assembly

Wire harness
ON
14
(DI-168)

Open in D squib circuit
Steering wheel pad (D squib)

Spiral cable

Airbag sensor assembly

Wire harness
ON
31
(DI-172)
Airbag sensor assembly malfunction
Airbag sensor assemblyON
54
(DI-174)
Open in P squib circuit
Front passenger airbag assembly (P squib)

Airbag sensor assembly

Wire harness
ON
HINT:

When the SRS warning light remains lit up and the DTC is the normal code, this means a source voltage
drops.
This malfunction is not stored in memory by the airbag sensor assembly and if the power source volt-
age returns to normal, the SRS warning light will automatically go out.

When 2 or more codes are indicated, the codes will be displayed in numeral order starting from the
lowest numbered code.

If a code not listed on the chart is displayed, the airbag sensor assembly is faulty.

DI4M8-01
N12263
Front Passenger
Airbag Assembly Steering Wheel Pad
(With Airbag)
Spiral Cable
Airbag Sensor Assembly
Instrument Panel
Junction BlockSRS Warning Light
DI-152
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
PARTS LOCATION

DI4MB-02
R15075
D squib (w/o Front Passenger Airbag)
1
Spiral
2
D
-
D+
Airbag Sensor Assembly
Cable
B
4
3 (w/ Front Passenger Airbag)
D squib
Spiral
Cable
1
2W
P squib1
22
1 D
-
D+2
1
P
-
P+
B
B W
W
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-155
1996 TERCEL (RM440U)
CIRCUIT INSPECTION
DTC 11 Short in Squib Circuit (to Ground)
CIRCUIT DESCRIPTION
The squib circuit consists of the airbag sensor assembly, spiral cable, steering wheel pad and front passen-
ger airbag assembly. If causes the SRS to deploy when the SRS deployment conditions are satisfied.
For details of the function of each component, see FUNCTION OF COMPONENTS on page RS-2.
DTC 11 is recorded when ground short is detected in the squib circuit.
DTC No.DTC Detection ConditionTrouble Area
11

Short circuit in squib wire harness (to ground)

Squib malfunction

Spiral cable malfunction

Airbag sensor assembly malfunction
Steering wheel pad (D squib)

Front passenger airbag assembly (P squib)

Spiral cable

Airbag sensor assembly

Wire harness
WIRING DIAGRAM

R05901
R14290H00004
Airbag Sensor
Assembly
P Squib
D SquibSpiral
Cable
D+
D-
DI-156
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Preparation. (See step 1 on page DI-177)
2 Check D squib circuit.
CHECK:
For the connector (on the spiral cable side) between the spiral
cable and steering wheel pad, measure the resistance between
D
+, D- and body ground.
OK:
Resistance: 1MW or higher
NG Go to step 7.
OK