1996 TOYOTA TERCEL Service Repair Manual

- DIAGNOSTICSENGINE
DI-75
1996 TERCEL (RM440U)
NG Repair or replace.
OK
Replace three-way catalytic converter.

DI-44
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0133 Oxygen Sensor Circuit Slow Response
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-38 .
DTC No.DTC Detection ConditionTrouble Area
P0133
Response time for oxygen sensor's voltage output to
change from rich to lean, or from lean to rich, is 1 sec. or
more during idling after the engine is warmed up
(2 trip detection logic)

Oxygen sensor
HINT:
Sensor 1 refers to the sensor closer to the engine body.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0133) being output?
YES Go to relevant DTC chart.
NO
Replace oxygen sensor.
DI1EC-07

A15711
P19752
Combination Meter
C8611
SPD5 V
E8 Y
C9
7 Speed
Sensor
BR
ID
ECM DI-76
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
This sensor is mounted in the combination meter. It contains a magnet which is rotated by the speedometer
cable.
Turning the reed switch ON and OFF 4 times for every revolution of the speedometer.
It is then transmitted to the ECM. The ECM determines the vehicle speed based on the frequency of these
pulse signals.
DTC No.DTC Detection ConditionTrouble Area
P0500
No vehicle speed sensor signal to ECM when vehicle is being
driven
(2 trip detection logic)
Open or short in vehicle speed sensor circuit

Vehicle speed sensor

Speedometer cable

ECM
WIRING DIAGRAM
DI01B-23

A15713
AT7809
4.5 - 5.5 V
0
Turn the wheel
- DIAGNOSTICSENGINE
DI-77
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit. See combination
meter troubleshooting.
OK
2 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the lower finish panel.
(b) Shift the shift lever to neutral.
(c) Jack up one of the front wheels.
(d) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal SPD of the ECM con-
nector and the body ground when the wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector be-
tween combination meter and ECM.
OK
Check and replace ECM (See page IN-26).

A15714
A15715
DI-78
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located on the throttle
body and intake air bypassing the throttle valve is directed to
the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle-up and
provide feedback for the target idling speed.
DTC No.DTC Detection ConditionTrouble Area
P0505Idle speed continues to vary greatly from the target speed
(2 trip detection logic)

IAC valve is stuck or closed

Open or short in IAC valve circuit

Open or short A/C 1 signal circuit

Air intake (hose loose)
WIRING DIAGRAM
DI4LK-02

A15716
- DIAGNOSTICSENGINE
DI-79
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check air induction system (See page MF-1).
NG Repair or replace.
OK
2 Check A/C signal circuit (See page AC-66).
NG Repair or replace.
OK
3 Check voltage between terminals RSO, RSC of ECM connector and body ground.
PREPARATION:
(a) Remove the lower finish panel.
(b) Disconnect the E7connector of ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal RSO and RSC of the
ECM connector and the body ground.
OK:
Voltage: 9 - 14 V
OK Go to step 5.
NG
4 Check IAC valve (See page MF-33).
NG Replace IAC valve.
OK

DI-80
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
Check for open and short in harness and connector between junction connector and IAC valve,
IAC valve and ECM (See page IN-26).
5 Check operation of IAC valve (See page MF-36).
NG Repair or replace IAC valve.
OK
Check and replace ECM (See page IN-26).

A15717
- DIAGNOSTICSENGINE
DI-81
1996 TERCEL (RM440U)
DTC P0510 Closed Throttle Position Switch Malfunction
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI-33.
DTC No.DTC Detection ConditionTrouble Area
P0510Closed throttle position switch does not turn ON even once
when vehicle is driven (2 trip detection logic)
Open in closed throttle position switch circuit

Closed throttle position switch

ECM
HINT:
After confirming DTC P0510, use the TOYOTA hand-held tester to confirm the closed throttle position switch
signal from the CURRENT DATA.
Throttle ValveClosed Throttle Position Switch SignalMalfunction
Fully closedOFFOpen circuit
Fully openONShort circuit
WIRING DIAGRAM
Refer to DTC P0120 on page DI-33.
INSPECTION PROCEDURE
HINT:
If DTCs P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
TOYOTA hand-held tester:
1 Check for open in harness or ECM.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Disconnect the throttle position sensor connector.
(c) Connect the sensor wire harness terminals between ter-
minals 3 and 4.
(d) Turn the ignition switch ON.
CHECK:
Read thg CTP switch signal on the TOYOTA hand-held tester.
OK:
CTP switch signal: ON
OK Confirm good connection at sensor. If OK, re-
place throttle position sensor.
NG
DI95R-01