1990 MITSUBISHI SPYDER ECU

ABS Troubleshooting
Code No. 16 Power supply system
[Comment]lMalfunction of wiring harness or connector,
This diagnostic trouble code is output when the ABS -ECU power voltage is outside
l Malfunction of battery or generator’
the standard value. Furthermore, if the voltage ret urns to normal, this diagnostic
l Malfunction of ABS-ECU
trouble code will not be output.
Caution
If the battery voltage drops during check, this cod e will be output as a current
and correct
diagnostic of the problem cannot be made.
Before carrying out the following check, check the battery condition;
Measure at the ABS-ECU connector
l
OK
5 4 9 , and
NG Repair. .
Check the or
. N G Check the following connector:
OK
Check trouble symptoms Replace ABS-ECU.
Code No. Wheel speed sensor gap
or short circuit
[Comment]l Improper installation of wheel speed sensor
These diagnostic trouble codes are output when the detection speed of the wheellMalfunction of wheel speed sensor (intermittent ope nspeed sensors is below the standard value.
circuit or short circuit)lMalfunction of ABS rotor (chipped tooth or rotor notinstalled)l Noise interference in wheel speed sensor
l Malfunction of ABS-ECU ,
TSB Revision
NOTE
1. Momentary interruptions within approximately 100 ms are not detected.
2. To inspect the twisted pair wires in the wheel s peed sensor, check if there is
cables, and flex the cables to check for any open c ircuits.
NG Repair
(Refer to
NGWheel speed sensor checkReplace the wheel speed sensor.check(Refer to(Refer to
Wheelspeedsensorbody-side harness

ABS
Code No. 38 Stop light switch system
[Comment]
The ABS-ECU outputs this diagnostic trouble code in the following cases.l Malfunction of stop light switch Malfunction of or lStop light switch remains on for more than 15 minutes while the ABS is . M a l f u n c t i o n ing.l The harness wire for the stop light switch may be o pen-circuited.If the stop light operates normally, there is an open circuit in the harness for the
stop light switch input circuit or there is a malfu nction in the ABS-ECU.
Yes
Stop light switch check (Refer to
GROUP On-vehicle Service.) Replace the
Measure at ABS-ECU connector l
Disconnect the connector and mea-
sure at the harness side.
l Stop light switch: ON
lVoltage between terminal 29 and body
ground
OK Battery positive
OK
Check the following connector:
l
OK
Check trouble symptom.
NG Repair
NG Replace the ABS-ECU.
Revision

ABS
Code No. Solenoid valve system
[Comment]l Malfunction of hydraulic unitThe ABS-ECU normally the solenoid valve drive circuit.
If no current flows in the solenoid even if ECU turns the solenoid ON or itl continues to flow even when turned OFF, the ECU det ermines the solenoid coil wireis broken/short-circuited or the harness is broken/ short-circuited, and then thesediagnostic trouble codes are output.
Measure at hydraulic unit connector l Disconnect the connector and Replace the hydraulic unit.
sure at the hydraulic l Resistance value between terminals
7-3, 7-5 and 7-6.
O K
NGMeasure at ABS-ECU connector l Disconnect the connector and mea-
sure at the harness side
l Resistance value between terminals
22-17. 22-19 and
Check the following NG Repair
OK
Check trouble symptom.NG Replace the ABS-ECU.
TSB Revision

Code No. 51 Valve Probable cause
[Comment] of ABS valve relayWhen the ignition switch is turned ON, the ABS-ECU switches relay OFF Malfunction of harness or and ON for an initial check, compares the voltage of the signal to the valve relay
l Malfunction of hydraulic unit and valve power monitor line voltage to. check whet her the valve relay is
l Malfunction of ABS-ECUnormal.In addition, normally it monitors whether or not th ere is power in the valvepower monitor line since the valve relay is normall y ON.
If the supply of power,to the valve power monitor line is interrupted, thi s diagnostic trouble code will beoutput.
A B S v a l v e r e l a y c h e c k ( R e f e r t oReplace, the ABS valve
Measure at hydraulic unit connector l Disconnect the connector and
lVoltage between terminal 12 and body
Repair
OK N G
Measure at ABS-ECU connector
l Disconnect the connector and mea-
sure at the harness side.
l Resistance value between terminals
OK
) R e p a i r
,
2 27
O K Check trouble symptom.
OK
l Disconnect the connector and
l
. NG Repair
OK
Check trouble symptom. Replace the ABS-ECU.
TSB Revision

Code No. 53 Motor relay, motor system
[Comment]The ABS-ECU outputs this diagnostic trouble code for the motor relay and motor
in the following cases.
lWhen motor relay is ON and no signal is input to th e motor monitor line (when
motor is not operating, etc.)
l
5 seconds or more (when motor continues operating, etc.)
l When the motor relay does not function
ABS motor relay check (Refer to
Inspect the harness between fusible
link No. 8 and the hydraulic unit.
Measure at ABS-ECU connector
l Disconnect the connector and Check the following l
NG,
OK
Check trouble
NG
Check the harness thehydraulic unit and ABS-ECU. Repair,if
l Disconnect the connector and
Revision
.
Repair.
OK
Check trouble symptom.NG Replace the ABS-ECU.

INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS .
INSPECTION PROCEDURE , .,, , __ ,
Communication with scan not possible. , .
(Communication with all is not Probablecause
[Comment]The reason is probably a defect in supply system (including ground) forl .
the diagnostic line.. . . .
Refer to GROUP -Troubleshooting.
.I N S P E C T I O N P R O C E D U R E 2
(Communication with ABS only is not
Communication with scan tool is ,
l Blown fuseWhen the s&an tool is not possible, the cause is probab ly anopen circuit in the ABS-ECU power circuit or an ope n circuit in the diagnostic outputl Malfunction of connector
l Malfunction of ABS-ECU
circuit.. . . .
NGMeasure at data link connector Repairand ABS-ECU connector -1.lDisconnect the connector and mea-sure at the side.
Continuity between the following
terminals.OK: Continuity
ABS-ECU side to Data link
connector side C h e c k t h e between the
ABS-ECU and link connector. . . necessary.
OK.NG NGMeasure at ABS-ECU connector RepairlDisconnect the connector and mea-* and sure at the harness side.
l Ignition switch ONOK
l Voltage between terminal 18 and ground. Check trouble symptomsOK: Battery positive voltage
OKCheck the harness between fuse No.
.13 the junction block andABS-ECU. Repair, if necessary. .
Measure at ABS-ECU connector . . lDisconnect the connector and mea-sure at the harness side.l and body ground..OK: Continuity
TSB Revision

ABS Troubleshooting , ,
INSPECTION PROCEDURE 3When ignition key is turned to “ON” (engine stopped ),
ABS warning light does not illuminate
[Comment]When power is supplied to the ABS-ECU, the valve relay changes from to ON by the initial check, and thus even if there is a problem with the circuit between
ABS light and ABS-ECU, the light will illuminate once when the valve relay
is OFF.
Accordingly, the cause of the light not illuminatin g is probably an open circuit in the
light power circuit, a blown light bulb, or an open circuit in both the circuit between
the ABS
light and the ABS-ECU and the circuit between the ABS light and the ABS valve relay.When other lights also do not illuminate, the cause is probably a blown fuse.
Measure at combination meter connector
l Disconnect the connector and mea-
sure at the harness side.
l Ignition Switch ON
lVoltage between terminal 10 and body
OK Battery positive voltage Check trouble symptoms
Measure at combination meter connector
sure at the combination meter side.
l Continuitv between terminals
R e p l a c e t h e
OK Continuity ,
OK
Check the harnesses between the ABS valve relay and the combination meter,
a n d b e t w e e n t h e A B S - E C U a n d
combination meter (common section).
if necessary.
INSPECTION PROCEDURE 4
TSB Revision.
Even after the engine is started, the ABS Warning l ight ,remains illuminated.. .
[Comment]There is probably a short in the ABS warning light illumination circuit.l Malfunction of combination meterl Malfunction of ABS valve relayl Malfunction of ABS-ECU. ,
NOTE
This trouble symptom is limited to cases where comm unication with the scan tool is’
is normal) and the diagnostic trouble code is a normal diagnostic trouble code..YESDisconnect the ABS-ECU connector Does the light remain illuminated?
NO
Short circuit inside the combination or in the harnessbetween the meter and
Replace the ABS-ECU.

When ignition key is turned ABS warning lightProbable.
does not illuminate.
[Comment]The ABS-ECU uses the the which is cut when the ignition switch is’l o f
turned to “START”. The ABS light uses power which is not cut even
l when the ignition switch is turned to “START”.Accordingly, because the power to the ABS-ECU is st
opped in “START” position,
if the light does not illuminate at this time, the cause is a problem in the __ light illumination circuit in the valve relay.
N GMeasure at hydraulic unit connector NG_..l Disconnect the connector and mea- Repair
sure at the harness side.lVoltaae between terminal and bodv
v o l t a g e trouble symptom.
Replace the hydraulic unit.
INSPECTION PROCEDURE 6
The ABS warning light flashes once after the igniti on key
Probable cause
is turned to “ON”. The light
when
is turned to “START”, and when the is to
it flashes once.I[Comment]l Malfunction of wiring harness or When power flows, the ABS-ECU turns on the warning light for approximately secondl Malfunction of ABS-ECU
while it performs a valve relay test. If there is a break in the harness between the
ECU and the
light illuminates only when the valve relay is off in valve
relay test, etc.
NGMeasure at ABS-ECU connector Check the connectors:
l Disconnect the connector and mea- a n d Repair
sure at the harness side.
combination meter and the ABS-ECU.Repair, if
.
,
Repair
OK
Check trouble symptom. Replace the ABS-ECU.
TSB RevisionI