Relay Circuit Malfunction - Suzuki Grand Vitara XL-7 Service Manual

6-1-30 ENGINE DIAGNOSIS (RHZ ENGINE WITH TRIPLE-CONNECTOR ECM)
DTC P0380 (P0380)/P1404 (P0380) PRE/POST HEAT RELAY CIRCUIT MALFUNCTION
WIRING DIAGRAM
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool.
3) Turn ignition switch ON for 30 sec. after OFF. Then run engine at idle speed for 30 sec.
4) Check DTC and pending DTC by using scan tool.
TROUBLESHOOTING
STEP
1 Was "ENGINE DIAG. FLOW TABLE"
performed?
2 Check Wire Harness
1) Remove ECM cover from ECM referring to
"CHECK VOLTAGE" in this section.
2) Check voltage between E229-7/E227-11
and ground with ignition switch ON.
Are they about 12 V?
3 Check Wire Harness
1) Check voltage between E229-3 and ground
with ignition switch ON.
Is it about 0 V?
ACTION YES
Go to Step 2.
Go to Step 3.
D Poor E229-7 or
E229-3 connection
If connections are in
good condition,
substitute a known-
good ECM and
recheck.
1. Pre post heating relay
(control unit)
2. ECM
3. Glow plugs
4. Main fuse
5. From ignition switch
NO
Go to "ENGINE DIAG.
FLOW TABLE".
D "LT BLU" wire open or
short to ground, or
D "BLK/WHT" wire open or
short to ground
D "GRN /BLU" wire open or
short,
D "BLK" wire (between
pre-post heating relay
and ground) open or
short to ground
D "BLK" wire (between
pre-post heating relay
and glow plug) open or
short to ground
D Poor glow plug "BLK"
wire terminal connection
If all are OK, substitute a
known-good ECM and
recheck.