Suzuki WagonR+ RB310 Service Manual page 2369

6-10 ENGINE DIAGNOSIS
PRECAUTION IN DIAGNOSING TROUBLE
D Don't disconnect couplers from ECM, battery cable from battery,
ECM ground wire harness from engine or main fuse before con-
firming diagnostic information (DTC, freeze frame data, etc.)
stored in ECM memory. Such disconnection will erase memo-
rized information in ECM memory.
D Diagnostic information stored in ECM memory can be cleared as
well as checked by using SUZUKI scan tool (Tech-1) or generic
scan tool. Before using scan tool, read its Operator's (Instruction)
Manual carefully to have good understanding as to what functions
are available and how to use it.
D Priorities for diagnosing troubles (Vehicle with EGR valve).
If troubleshooting priorities for multiple diagnostic codes are giv-
en in the applicable DTC flow chart, these should be followed.
If no instructions are given, troubleshoot diagnostic trouble codes
according to the following priorities.
1. Diagnostic trouble
P0171/P0172 (Fuel system too lean/too rich), DTC
P0300/P0301/P0302/P0303/P0304 (Misfire detected) and
DTC P0400 (EGR flow malfunction)
2. DTC P0171/P0172 (Fuel system too lean/too rich) and DTC
P0400 (EGR flow malfunction)
3. DTC P0300/P0301/P0302/P0303/P0304 (Misfire detected)
D Be sure to read "Precautions for Electrical Circuit Service" in Sec-
tion 0A before inspection and observe what is written there.
D ECM Replacement
When substituting a known-good ECM, check for following condi-
tions. Neglecting this check may cause damage to a known-good
ECM.
– Resistance value of all relays, actuators is as specified respec-
tively.
– MAP sensor and TP sensor are in good condition and none of
power circuits of these sensors is shorted to ground.
codes (DTCs) other than DTC