Source: http://mazda626.net/topic/39240-djdevon3s-guide-how-to-pull-obd-i-codes-1993-1995-i4-or-v6/
MECS-II (OBD-I)
Diagnostics
1993-1995 Mazda
MX-6/626/Ford Probe
(2.0L MTX & 2.5L ATX or
MTX)
Source:
http://homepage.ntlw...nt.htm#malfsrso
Source:
http://www.scpoc.com...ntMod/codes.htm
USA MECS-II Diagnostic
Connector
To enter the car into
diagnostic mode for MCU
or MECS-II you must
jumper pins C (TEN) and
E (GND). However if
that does not work (as
might be the case on
European versions) then
try to jumper pin C
(TEN) to the negative
battery terminal.
European MECS-II Diagnostic Connector
To learn about the
steps after getting your
car into diagnostic mode
for MECSII equipped
vehicles please read
Snailman's guide.
A = FEN = trouble code
output (engine control
computer)
B = MEN = switch monitor
output (engine control
computer)
C = TEN =
diagnostic-mode input
(engine control
computer)
D = +B = switched
battery voltage
E = GND = ground
F = FAT = trouble code
output (automatic
transmission control
computer)
G = FBS = trouble code
output (anti-lock brakes
(ABS) control computer)
H = FAC = trouble code
output (? not documented
for North American
vehicles)
J = FWS = trouble code
output (? not documented
for North American
vehicles)
K = FSC = trouble code
output (cruise (speed)
control computer)
L = - = not used
M = TAT =
diagnostic-mode input
(automatic transmission
control computer)
N = TBS =
diagnostic-mode input
(anti-lock brakes (ABS)
control computer)
P = TAC =
diagnostic-mode input (?
not documented for North
American vehicles)
Q = TWS =
diagnostic-mode input (?
not documented for North
American vehicles)
R = TSC =
diagnostic-mode input
(cruise (speed) control
computer)
S = - = not used
T = FAB = trouble code
output (air-bag
diagnostic monitor
computer)
U = IG- = igniter coil
output (for connection
to external tachometer)
V = GND = ground
W = TFA =
diagnostic-mode input (?
not documented for North
American vehicles)
X = F/P = fuel pump
relay coil (ground to
activate fuel pump)
Y = TAB = horn relay
Z = - = not used
3 = - = not used
MECS-II (CEL) Check
Engine Light codes
These are the main check
engine light codes for
MECS-II 626's. You put
the car into diagnostic
mode by using a jumper
wire between the C (TEN)
& E (GROUND) pins of
the diagnostic box under
the hood of your car.
Code = Memory = Circuit
Diagnosed
02 = Yes = 'NE2'
crankshaft position
sensor
03 = Yes = 'G' camshaft
position sensor
04 = Yes = 'NE1'
camshaft/crankshaft
position sensor
05 = Yes = Knock sensor
08 = Yes = Volume Air
Flow sensor (VAF)
09 = Yes = Coolant
temperature sensor (CTS)
10 = Yes = Intake air
temperature sensor (IAT)
12 = Yes = Throttle
position sensor (TPS)
14 = Yes = Barometric
pressure sensor
15 = Yes = LHO2S
inactivation error
16 = Yes = Exhaust gas
recirculation (EGR)
system
17 = Yes = LHO2S
inversion error
23 = Yes = RHO2S
inactivation error
24 = Yes = RHO2S
inversion error
25 = Yes = Fuel pressure
regulator control
solenoid
26 = No = Canister purge
solenoid
28 = No = EGR vacuum
solenoid
29 = No = EGR vent
solenoid
34 = No = Idle air
control (IAC) solenoid
41 = No = VRIS #1
solenoid
46 = No = VRIS #2
solenoid
67 = No = LFAN relay
(1993 only)
69 = Yes = ECTF sensor
(1993 only)
(HOLD) Automatic
Transmission (ATX)
Malfunction codes
Automatic transmission
codes can be read by
connecting the TAT and
GND pins (see above for
the location of this
pin) and watching the
"hold" light on the
instrument cluster. The
codes are read exactly
as they are when reading
the engine codes, except
that the Hold light
flashes, not the Check
Engine Light. A summary
of the codes and the
reasons:
01 = NE1 (crankshaft
position sensor)
06 = Vehicle speed
sensor
12 = Throttle position
sensor
14 = BARO sensor
(located within PCME)
55 = Vehicle speed pulse
generator
56 = ATF thermosensor
57 = Reduce torque
signal 1
58 = Reduce torque
signal 2
59 = Torque reduced/ECT
sensor
60 = 1-2 shift solenoid
valve
61 = 2-3 shift solenoid
valve
62 = 3-4 shift solenoid
valve
63 = converter lock-up
solenoid valve
64 = 3-2 timing solenoid
valve
65 = converter lock-up
valve
66 = line pressure
solenoid valve
(ABS) Anti-Lock Braking
System Malfunction codes
Anti-lock braking (ABS)
system codes are read
when the TBS and GND
pins are connected in
the Diagnostic connector
(see above). The codes
are read, again, like
the engine codes, but
now on the ABS light on
the instrument cluster.
A summary of codes and
the reasons:
11 = Right front wheel
speed sensor or rotor
12 = Left front wheel
speed sensor or rotor
13 = Right rear wheel
speed sensor or rotor
14 = Left rear wheel
speed sensor or rotor
15 = Wheel speed sensor
22 = Hydraulic unit
harness
51 = Fail-safe relay
53 = Motor or motor
relay
61 = ABS control unit
(SRS) Supplemental
Restraint System
Malfunction codes
The supplemental
restraint (SRS), more
commonly known as the
"air bag" system will
flash the highest
priority code on the
air-bag lamp on the dash
with no need for any pin
in the Diagnostic box to
be grounded. The codes
are read, again, like
the engine codes, but
now on the Air Bag light
on the instrument
cluster. A summary of
codes and the reasons
(NOTE: these are from a
1993 Ford Service
Manual. Later models
with dual airbags
(1994+) may have
additional codes not
covered here. Email me
if you encounter one.
Also, I hope but am
unsure if these apply to
the MX-6...):
In order of priority
from highest to lowest:
- = No air bag lamp:
diagnostic monitor (DM),
ignition power or bulb
circuit
- = Continuous lamp: DM
disconnected or
inoperative
12 = Low battery voltage
13 = Air bag circuit or
crash sensor shorted to
ground
21 = Safing sensor
mounted incorrectly
22 = Safing sensor:
output shorted to
battery voltage
23 = Safing sensor input
feed or return circuit
open
24 = Open in circuit
944B or low-resistance
in crash sensor(s)
32 = Driver's side
air-bag / safing sensor:
high resistance or open
33 = Pin 7 not grounded
at DM
34 = Driver's side
air-bag / safing sensor:
low resistance or
shorted
35 = Low resistance
across pins 8 and 9 of
DM
41 = Crash sensor
circuit: high resistance
or open
44 = RH crash sensor not
mounted properly
45 = Center (radiator)
crash sensor not mounted
properly
46 = LH crash sensor not
mounted properly
51 = DM internal fuse:
blown and short to
ground no longer exists
52 = Backup-power
supply: voltage boost
fault
53 = Internal DM fault
- = Rapid continuous
flashing or air-bag
lamp: all crash sensors
disconnected