2004 DAEWOO LACETTI Service Repair Manual

Page 817 of 2643

DAEWOO LACETTI 2004  Service Repair Manual ENGINE CONTROLS  1F – 571
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1631
IMMOBILIZER INVALID RESPONSE
Circuit Description
The Engine Control Module (ECM) is the control center of
the fuel in

Page 818 of 2643

DAEWOO LACETTI 2004  Service Repair Manual 1F – 572IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1650
SPI COMMUNICATION BETWEEN ERROR WITH SIDM
CHIP
Circuit Description
The Engine Control Module (ECM) is the control cent

Page 819 of 2643

DAEWOO LACETTI 2004  Service Repair Manual ENGINE CONTROLS  1F – 573
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1655
SPI COMMUNICATION BETWEEN ERROR WITH PSVI
CHIP
Circuit Description
The Engine Control Module (ECM) is the control cen

Page 820 of 2643

DAEWOO LACETTI 2004  Service Repair Manual 1F – 574IENGINE CONTROLS
DAEWOO V–121 BL4
SYMPTOM DIAGNOSIS
IMPORTANT PRELIMINARY CHECKS
Important : Several symptom procedures call for a careful visual/physical inspection. Always perform the vi

Page 821 of 2643

DAEWOO LACETTI 2004  Service Repair Manual ENGINE CONTROLS  1F – 575
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
5Replace the sensor in the affected circuit, if a Diag-
nostic Trouble Code (DTC) was stored for this circuit
(except for the

Page 822 of 2643

DAEWOO LACETTI 2004  Service Repair Manual 1F – 576IENGINE CONTROLS
DAEWOO V–121 BL4
HARD START
Definition : The engine cranks OK, but does not start for
a long time. The engine eventually runs or may start and
immediately die.Important :

Page 823 of 2643

DAEWOO LACETTI 2004  Service Repair Manual ENGINE CONTROLS  1F – 577
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
101.  Check the fuel injector driver circuit.
2.  Disconnect all of the fuel injector harness con-
nectors at the fuel injecto

Page 824 of 2643

DAEWOO LACETTI 2004  Service Repair Manual 1F – 578IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
231.  Check for the proper valve timing.
2.  Check the cylinder compression.
3.  Inspect the pushrods, the rocker arms, the
val