Precaution In Diagnosing Trouble - Suzuki Swift User Manual

7B-12 AUTOMATIC TRANSMISSION (3 A / T) (VEHICLE WITH WU-TWC)

PRECAUTION IN DIAGNOSING TROUBLE

D Don't disconnect couplers from PCM, battery cable from battery, PMC ground wire harness from engine or main
fuse before checking the diagnosis information (DTC, freeze frame data, etc.) stored in PCM memory.
Such disconnection will clear memorized information in PCM.
D Using SUZUKI scan tool (Tech-1) 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 supplied with it carefully to have good
understanding of its functions and usage.
D Priorities for diagnosing troubles
If two or more diagnostic trouble codes (DTCs) are stored, proceed to flow table (chart) of DTC which was de-
tected earliest in order and follow instruction in that table (chart).
If no instructions are given, troubleshoot diagnostic trouble codes according to the following priorities.
1. Diagnostic trouble codes (DTCs) other than DTC 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 "PRECAUTION FOR ELECTRICAL CIRCUIT SERVICE" in Section 0A before inspection and
observe what is written there.
D PCM replacement
When substituting a known-good PCM, check for following conditions.
Neglecting this check may result in damage to good PCM.
– All relays and actuators have resistance of specified value.
– MAF sensor, TP sensor and fuel tank pressure sensor (if equipped) are in good condition. Also, the power cir-
cuit of these sensors is not shorted to the ground.