Troubleshooting
DTC 1-2: Pump Motor
The ABS control unit checks the conditions at the pump motor relay drive (PMR) terminal and motor check (MCK) terminal
during the initial diagnosis and regular diagnosis. When the ABS control unit detects the following conditions during the
diagnosis, it keeps the ABS indicator light on. When the following conditions are detected after the ABS indicator light
goes off, the ABS control unit turns the ABS indicator light on again.
Battery voltage at the MCK terminal with an OFF signal at the PMR terminal
O V at the MCK terminal with an ON signal at the PMR terminal
Possible causes:
Open circuit or short to body ground between the R/C MIRROR (7.5 A) fuse and under-hood fuse/relay box
Open circuit or short to body ground in the PMR circuit inside the under-hood fuse/relay box
Faulty pump motor relay
Open circuit or short to body ground in the PMR circuit between the under-hood fuse/relay box and ABS control unit
Open circuit between the battery and under-hood fuse/relay box
Blown ABS MOTOR (40 A) fuse
Blown ABS UNIT (7.5 A) fuse
Open circuit or short to body ground in the motor drive circuit and MCK circuit inside the under-hood fuse/relay box
Open circuit or short to body ground in the MCK circuit between the under-hood fuse/relay box and ABS control unit
Open circuit or short to body ground between the under-hood fuse/relay box and pump motor
Faulty pump motor
Open circuit between the pump motor and body ground or poor ground
Faulty ABS control unit
With engine running, ABS indi-
cator light is ON.
With the SCS service connec-
tor connected (see page
19-40
), DTC 1-2 is indicated.
UNDER-HOOD FUSE/RELAY BOX
ABS PUMP MOTOR RELAY
ABS UNIT (7.5 A) FUSE
Check the ABS MOTOR (40 A) fuse
in the under-hood fuse/relay box.
Is the fuse OK?
Replace the fuse and recheck.
NOTE: Reinstall the fuse if it is OK.
ABS MOTOR (40 A) FUSE
Is the fuse OK?
Replace the fuse and recheck.
YES
NOTE: Reinstall
the fuse if it is OK.
NOTE: Relieve system pressure from the
modulator unit bleed screw, then start the
engine and recheck the fuse. If the fuse is
blown, check for a short to body ground in
the MCK circuit.
(To page
19-51
)
Main Menu
Table of Contents