Precaution In Diagnosing Trouble - Suzuki GRAND VITARA XL-7 Owner's Manual

Precaution in Diagnosing Trouble

• Don't disconnect couplers from PCM (ECM), battery cable
from battery, PCM ground wire harness from engine or main
fuse before checking the diagnosis information (DTC, freeze
frame data, etc.) stored in PCM memory. Such disconnec-
tion will clear memorized information in PCM memory.
• Using SUZUKI scan tool or also generic scan tool for vehicle
without monitor connector, the diagnostic information stored
in PCM memory can be checked and cleared as well. Before
its use, be sure to read Operator's (Instruction) Manual sup-
plied with it carefully to have good understanding of its func-
tions and usage.
• Priorities for diagnosing troubles
If two or more diagnostic trouble codes (DTCs) are stored,
proceed to the flow table of the DTC which was detected
earliest in the order and follow the instruction in that table.
If no instructions are given, troubleshoot diagnostic trouble
codes according to the following priorities.
– Diagnostic trouble codes (DTCs) other than DTC P0171/
P0172/P0174/P0175 (Fuel system too lean/too rich), DTC
P0300/P0301/P0302/P0303/P0304/P0305/P0306 (Misfire
detected) and DTC P0400 (EGR flow malfunction)
– DTC P0171/P0172/P0174/P0175 (Fuel system too lean/too
rich) and DTC P0400 (EGR flow malfunction)
– DTC P0300/P0301/P0302/P0303/P0304/P0305/P0306
(Misfire detected)
• Be sure to read "PRECAUTIONS FOR ELECTRICAL CIR-
CUIT SERVICE" in Section 0A before inspection and
observe what is written there.
• PCM replacement
When substituting a known-good PCM, check for following
conditions.
Neglecting this check may result in damage to a good PCM.
– All relays and actuators have resistance of specified value.
– MAF sensor, MDP sensor, TP sensor and fuel tank pres-
sure sensor are in good condition. Also, the power circuit of
these sensors is not shorted to the ground.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-9