Suzuki WagonR+ RB310 Service Manual page 1853

6-1-90 GENERAL INFORMATION AND ENGINE DIAGNOSIS
DTC P1510 ECM (PCM) BACK-UP POWER SUPPLY MALFUNCTION
CIRCUIT DESCRIPTION
Main
fuse
"DOME
RADIO"
Battery voltage is supplied so that diagnostic trouble code memory, values for engine control learned by ECM
(PCM), etc. are kept in ECM (PCM) even when the ignition switch is turned OFF.
DTC DETECTING CONDITION
D Low voltage at terminal E21-14 after starting engine.
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and run it at idle for 1 min.
2) Select "DTC" mode on scan tool and check DTC.
INSPECTION
STEP
1 Check for voltage at terminal E21-14 of ECM
(PCM) connector connected, under each
condition, ignition switch OFF and engine
running.
Is it 10 – 14 V at each condition?
To DLC
ACTION
POSSIBLE CAUSE
D "WHT /BLU" circuit open
D ECM (PCM) malfunction
YES
Poor E21-14
connection or
intermittent trouble.
Check for intermittent
referring to "Intermittent
and Poor Connection"
in Section 0A.
If wire and connections
are OK, substitute a
known- good ECM
(PCM) and recheck.
NO
"WHT /BLU" circuit
open.