Spark Test; Egr Control System Inspection - Mazda CX-7 2007 Workshop Manual

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

Spark Test

1. Disconnect the fuel pump relay.
2. Verify that each ignition coil and connector is connected properly.
3. Inspect the ignition system in the following procedure.
Warning
• High voltage in the ignition system can cause strong electrical shock which can result in serious
injury. Avoid direct contact to the vehicle body during the following spark test.
STEP
• Disconnect the ignition coil from the spark
1
plugs.
• Remove the spark plugs.
• Verify that the spark plugs do not have
carbon deposits.
• Are the spark plugs normal?
• Inspect the spark plugs for damage, wear,
2
and proper plug gap.
• Are the spark plugs normal?
• Reconnect the spark plugs to the ignition
3
coil.
• Ground the spark plugs to the engine.
• Is a strong blue spark visible at each cylinder
while cranking the engine?
• Inspect the following wiring harnesses for an
4
open or short circuit:
— Ignition coil No.1 terminal C—PCM
terminal 2BA
— Ignition coil No.2 terminal C—PCM
terminal 2AW
— Ignition coil No.3 terminal C—PCM
terminal 2AX
— Ignition coil No.4 terminal C—PCM
terminal 2AT
• Are the wiring harnesses normal?
• Measure the voltage at terminal A in each
5
ignition coils.
• Is the voltage B+?
• Does the PCM connector or ignition coil
6
connectors have poor connection?
• Are the following parts normal?
7
— CKP sensor and crankshaft pulley

EGR Control System Inspection

If simulation function of M-MDS is used:
1. Crank the engine and verify that the EGR valve operation (initial operation) sound is heard.
• If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403 is
shown. Perform the DTC inspection. (See01-02-13 DTC TABLE[L3 WITH TC].)
2. Start the engine run it is idling.
3. Increase the step value of the EGR valve from 0 to 57 using the SEGR PID of the simulation function.
4. Operate the EGR valve and inspect if the engine speed becomes unstable or the engine stalls.
• If the engine speed does not change, proceed to the following.
(1) Stop the engine.
(2) Remove the EGR valve.
(3) Connect the EGR valve connector.
(4) Turn the ignition switch to the ON position.
(5) Increase the step value of EGR valve from 0 to 57 using SEGRP PID.
(6) Verify that the EGR valve operates according to the SEGRP PID.
• If the EGR valve is operated, clean the EGR valve and the EGR gas passage.
• If the EGR valve does not operate, replace the EGR valve.
5. Start the engine and warm it up completely.
6. Access the following PIDs.
• ECT, RPM, SEGRP, APP1, APP2, TP_REL, VSS
7. Idle the vehicle and verify that the SEGRP value is 0.
Revised 8/2006 (Ref. No. R087/06)
2007 Mazda CX-7 Workshop Manual (1871–1U–06B)
INSPECTION
Yes Go to the next step.
No Perform no-load racing at 4,000 rpm for 2 min, 2 times to
burn off the carbon deposits.
Repeat Step 1.
Yes Go to the next step.
No Replace spark plugs, then go to the next step.
Yes Ignition system is normal.
No Some cylinders do not spark:
• Go to the next step.
All cylinders do not spark:
• Go to Step 5.
Yes Inspect and replace the ignition coil.
(See01-18-2 IGNITION COIL INSPECTION[L3 WITH TC].)
No Repair or replace the malfunctioning part, then go to Step 1.
Yes Go to the next step.
No Inspect the power supply circuit of ignition coils.
Yes Repair or replace the connector, then go to Step 1.
No Go to the next step.
Yes Inspect for an open or short circuit in the wiring harness and
connector of the CKP sensor.
No Repair or replace the malfunctioning part, then go to Step 1.
ACTION
01-03–87
01-03