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P1656 PDF

This document provides the diagnostic procedure for trouble code P1656 "OCV Circuit Malfunction" on a 2002 Toyota Echo. There are inspection steps to check the operation of the oil control valve (OCV) using a Toyota hand-held tester or OBD II scan tool. If the OCV operation check fails, the OCV should be replaced. If it passes, the voltage between OCV terminals and ECM should be checked and the ECM replaced if faulty. Finally, the harness and connectors between the OCV and ECM are checked for opens or shorts.

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Talleban Tal
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3K views3 pages

P1656 PDF

This document provides the diagnostic procedure for trouble code P1656 "OCV Circuit Malfunction" on a 2002 Toyota Echo. There are inspection steps to check the operation of the oil control valve (OCV) using a Toyota hand-held tester or OBD II scan tool. If the OCV operation check fails, the OCV should be replaced. If it passes, the voltage between OCV terminals and ECM should be checked and the ECM replaced if faulty. Finally, the harness and connectors between the OCV and ECM are checked for opens or shorts.

Uploaded by

Talleban Tal
Copyright
© Attribution Non-Commercial (BY-NC)
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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DI-134

DIAGNOSTICS ENGINE
DI6VO-04

DTC

P1656

OCV Circuit Malfunction

CIRCUIT DESCRIPTION
Refer to DTC P1349 (VVT System Malfunction) on page DI-122 .
DTC No. P1656 P1663 DTC Detecting Condition Open or short in oil control valve circuit Trouble Area S Open or short in oil control valve circuit S Oil control valve S ECM

WIRING DIAGRAM
Refer to DTC P1349 (VVT System Malfunction) on page DI-122 for the WIRING DIAGRAM.

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.

TOYOTA hand-held tester


1 Check OCV circuit.

PREPARATION: (a) Start the engine and warmed it up. (b) Connect the TOYOTA hand-held tester and select VVT from ACTIVE TEST menu. CHECK: Check the engine speed when operate the OCV by the TOYOTA hand-held tester. OK: VVT system is OFF (OCV is OFF): Normal engine speed VVT system is ON (OCV is ON): Rough idle or engine stalled OK Check for intermittent problems (See page DI-3 ).

NG

2002 ECHO (RM884U)

Author :

Date :

304

DI-135
DIAGNOSTICS ENGINE

Check operation of OCV.


START

BE6653 A09112

A09115

PREPARATION: (a) Start the engine and warmed it up. (b) Disconnect the OCV connector. (c) Apply battery positive voltage between terminals of the OCV. CHECK: Check the engine speed. OK: Rough idle or engine stalled. NG Replace OCV.

OK

Check voltage between terminals OCV+ and OCV- of ECM connector (See page DI-122 ).

NG

Check and replace ECM (See page IN-29 ).

OK

Check for open and short in harness and connector between OCV and ECM (See page IN-29 ).

NG

Repair or replace.

OK

Check for intermitent problems (See page DI-3 ).

2002 ECHO (RM884U)

Author :

Date :

305

DI-136
DIAGNOSTICS ENGINE

OBD II scan tool (excluding TOYOTA hand-held tester)


1 Check operation of OCV.
START

BE6653 A09112

A09115

PREPARATION: (a) Start the engine and warmed it up. (b) Disconnect the OCV connector. (c) Apply battery positive voltage between terminals of the OCV. CHECK: Check the engine speed. OK: Rough idle or engine stalled NG Replace OCV.

OK

Check voltage between terminals OCV+ and OCV- of ECM connector (See page DI-122 ).

NG

Check and replace ECM (See page IN-29 ).

OK

Check for open and short in harness and connector between OCV and ECM (See page IN-29 ).

NG

Repair or replace.

OK

Check for intermitent problems (See page DI-3 ).

2002 ECHO (RM884U)

Author :

Date :

306

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