Mazda CX-7 2007 Workshop Manual page 380

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
Investigate the electrical supply system for variable resistance type 2
• Confirm that the sensor #3 terminal is B+.
— If the measured voltage on the #3 terminal is B+, inspect the following points on the sensor connector.
— If there is no problem, inspect for the following:
• Female terminal opening is loose.
• Coupler (pin holder) damage
• Pin discoloration (blackness)
— If the #3 terminal measures other than B+, inspect the following:
• Open or short circuit in wiring harness
• Wiring harness/pin crimp is loose or disconnected.
Thermistor type (IAT sensor and ECT sensor)
Investigate the input signal system for thermistor type
1. When an unusual signal is received, measure the #1 PCM terminal voltage.
• If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step.
• If there is a difference of 0.5 V or more, inspect the following points concerning the PCM connector:
— Female terminal opening loose
— Coupler (pin holder) damage
— Pin discoloration (blackness)
— Wiring harness/pin crimp is loose or disconnected.
2. Measure the #2 sensor terminal voltage.
• If there is a 0.5 V or more difference between the sensor and M-MDS voltages, inspect the wiring harness
for open or short circuits.
• If the sensor and M-MDS voltages are the same, inspect the following points concerning the sensor
connector:
— Female terminal opening is loose.
— Coupler (pin holder) damage
— Pin discoloration (blackness)
— Wiring harness/pin crimp is loose or disconnected.
• If there are no problems, proceed to next investigation below.
Investigate the ground system for thermistor type
• Confirm that terminal sensor #3 is at 0 V.
— If it is at 0 V, inspect the sensor. If necessary, replace the sensor.
— If not, inspect for the following:
• Open circuit in wiring harness
• Female terminal opening is loose.
• Coupler (pin holder) damage
• Pin discoloration (blackness)
• Wiring harness/pin crimp is loose or disconnected.
01-03–80
PCM
1 2
INPUT
GND 4 3
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