Service Manuals, User Guides, Schematic Diagrams or docs for : . Car Manuals Toyota Echo 2000-2002 Approved techinfo.toyota.com ileaf 02toyrm 02toypdf 02rmsour 2002 02echorm di eg cip0420
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download cip0420 documenatation <<
Text preview - extract from the document
DI-77
DIAGNOSTICS - ENGINE
DI6VC-04
DTC P0420 Catalyst System Efficiency Below Threshold
CIRCUIT DESCRIPTION
The ECM compares the waveform of the oxygen sensor located before the catalyst with the waveform of
the oxygen sensor located behind the catalyst to determine whether or not catalyst performance has deterio-
rated.
Air-fuel ratio feedback compensation keeps the waveform of the oxygen sensor before the catalyst repeat-
edly changing back and forth from rich to lean.
If the catalyst is functioning normally, the waveform of the oxygen sensor behind the catalyst switches back
and forth between rich and lean much more slowly than the waveform of the oxygen sensor before the cata-
lyst.
But when both waveforms change at a similar rate, it indicates that catalyst performance has deteriorated.
Waveform of Heated Oxygen Waveform of Heated Oxygen
Normal Catalyst
Sensor before Catalyst Sensor behind Catalyst
FI7081
DTC No. DTC Detecting Condition Trouble Area
After the engine and the catalyst are warmed up, and while the
S Gas leakage on exhaust system
vehicle is driven within the set vehicle and engine speed range,
S Open or short in heated oxygen sensor circuit
P0420 the waveforms of the oxygen sensors (bank 1 sensor 1 and
S Heated oxygen sensor
bank 1 sensor 2) have the same amplitude
S Three-way catalytic converter
(2 trip detection logic)
2002 ECHO (RM884U)
Author : Date : 247
DI-78
DIAGNOSTICS - ENGINE
CONFIRMATION ENGINE RACING PATTERN
Engine Speed
(c) (d)
2,500 3,000 rpm
(b)
Idling
IG SW OFF
(a)
Warmed up 3 min. or so Check Time
FI7132
(a) Connect the TOYOTA hand-held tester to the DLC3, or connect the probe of the oscilloscope between
terminals OX1, OX2 and E1 of the ECM connector.
(b) Start engine and warm it up with all accessories switched OFF until water temp. is stable.
(c) Race the engine at 2,500 - 3,000 rpm for about 3 min.
(d) After confirming that the waveforms of the oxygen sensor, bank 1 sensor 1 (OX1), oscillate around 0.5
V during feedback to the ECM, check the waveform of the oxygen sensor, bank 1 sensor 2 (OX2).
HINT:
OX Signal Waveform (Oscilloscope)
S If there is a malfunction in the system, the waveform of the
1.0 V oxygen sensor, bank 1 sensor 2 (OX2), is almost the
same as that of the oxygen sensor, bank 1 sensor 1
(OX1), on the left.
S There are some cases where, even though a malfunction
0V
exists, the MIL may either light up or not light up.
200 m sec. /Division FI6514
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air-fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Are there any other codes (besides DTC P0420) being output?
YES Go to relevant DTC chart (See page DI-14 ).
2002 ECHO (RM884U)
Author : Date : 248
DI-79
DIAGNOSTICS - ENGINE
NO
2 Check gas leakade on exhaust system.
NG Repair or replace exhaust system.
OK
3 Check oxygen sensor (bank 1 sensor 1) (See page DI-48 ).
NG Repair or replace oxygen sensor (bank 1 sen-
sor 1).
OK
4 Check oxygen sensor (bank 1 sensor 2) (See page DI-57 ).
NG Repair or replace oxygen sensor (bank 1 sen-
sor 2).
OK
Replace three-way catalytic converter.
2002 ECHO (RM884U)
Author : Date : 249
◦ Jabse Service Manual Search 2024 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo