Mazda MX-5 Miata Sport 2007 Manual page 1965

2007 ENGINE PERFORMANCE Symptom Troubleshooting - MX-5 Miata
12 Attempt to start engine
at part throttle.
Does engine run
smoothly at part
throttle?
13 Connect the M-MDS or
equivalent to the DLC-
2. Access RPM PID.
Is RPM PID indicating
engine speed during
engine cranking?
2007 Mazda MX-5 Miata Sport
No
Yes
No
Yes
No
Open circuit in wiring

harness between main
relay and PCM terminal
1AW or 1BE
Open main relay GND

circuit
Main relay is stuck open.

Open or short circuit in

wiring harness between
DLC and PCM terminals
1AM or 1AI
Open or poor GND circuit

(PCM terminal 1AZ,
1BB, 1BD, 1BH)
Poor connection of

vehicle body GND
No DTC is displayed:
Go to the next step.
Inspect electronic throttle
control system operation. (See
ELECTRONIC THROTTLE
CONTROL SYSTEM
INSPECTION .)
Go to the next step.
Go to the next step.
Inspect for the following:
Open or short circuit in

CKP sensor
Open or short circuit in

wiring harness between
CKP sensor terminal A
and PCM terminal 2AB
Open or short circuit in

wiring harness between
CKP sensor terminal B
and PCM terminal 2W
Open or short circuit in

wiring harness between
CKP sensor terminal C
and PCM terminal 2AQ
Open or short circuit in

CKP sensor wiring
harnesses