Toyota p1600 User Manual

DI–133

–DIAGNOSTICS ENGINE

DI38N–03

DTC P1600 ECM BATT Malfunction

CIRCUIT DESCRIPTION

Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for use by the DTC memory and air–fuel ratio adaptive control value memory, etc.

DTC No. DTC Detecting Condition Trouble Area

P1600 Open in back up power source circuit

HINT: If DTC P1600 appear, the ECM does not store another DTC.

WIRING DIAGRAM

S Open in back up power source circuit S ECM

ECM

Engine Room J/B

FL Main

Battery

B–R

EFI

BATT

A05723

INSPECTION PROCEDURE

HINT: Read freeze frame data using T OYOTA 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.

2000 CELICA (RM744U)

DI–134

–DIAGNOSTICS ENGINE

1 Check voltage between terminal BATT of ECM connector and body ground.

A09084

2 Check EFI fuse.

Engine Room J/B

BATT (+)

A09092

PREPARATION:

Remove the ECM cover.

CHECK:

Measure voltage between terminal BATT of the ECM connector and body ground.

OK:

Voltage 9 – 14 V

OK Check and replace ECM (See page IN–30).

PREPARATION:

Remove the EFI fuse from the engine room J/B.

CHECK:

Check continuity of EFI fuse.

OK:

Continuity

I11732

EFI Fuse

A11409

Check and repair harness or connector between battery and EFI fuse and ECM (See page IN–30).

NG Check for short in all the harness and

components connected to EFI fuse.

2000 CELICA (RM744U)