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Home >> Mazda >> 2002 >> Tribute LX, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 393 (Symptom Troubleshooting (Engine Control System) AJ) >> No.5 Engine Stalls-After Start/At Idle >> Diagnostic procedure

Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
ENGINE STALLS-AFTER START/AT IDLE - DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1
NOTE:
  • Following test should be performed on vehicles with immobilizer system. Go to Step 12 for vehicles without immobilizer system.
  • Connect WDS or equivalent to DLC-2.
  • Do following conditions appear?
    • Engine is not completely started.
    • DTC P1624 is displayed.
 Yes Both conditions appear: 
  • Go to Step 4.
No Either or other condition appear: 
  • Go to next step.
2
  • Does engine stall after approx. 2 seconds  since engine is started?
 Yes Go to next step.
No Immobilizer system is okay.
Go to Step 12.
3
  • Is immobilizer unit connector securely connected to immobilizer unit?
 Yes Go to next step.
No Connect immobilizer unit connector securely.
Return to Step 2.
4
  • Does immobilizer indicator light flash and indicate any of following immobilizer system DTCs?
DTC 01,02,03,11,21 		 Yes Go to "ON-BOARD DIAGNOSTIC FUNCTION" of immobilizer system.
No Go to next step.
5
  • Does immobilizer indicator light illuminate?
 Yes Go to Step 8.
No Go to next step.
6
  • Does immobilizer indicator light flash and indicate following immobilizer system DTC after more than 135 seconds  after ignition key is turned to ON?
DTC 24,30 		 Yes Go to "ON-BOARD DIAGNOSTIC FUNCTION" of immobilizer system.
No Go to next step.
7
  • Turn ignition key to OFF.
  • Disconnect immobilizer unit connector.
  • Connect jumper wire between immobilizer unit connector terminal M and GND.
  • Turn ignition key to ON (Engine OFF).
  • Does immobilizer indicator light illuminate?
 Yes Reconnect immobilizer unit connector.
Go to next step.
No Inspect for open circuit between immobilizer unit connector terminal M and instrument cluster.
  • If okay, inspect immobilizer indicator light bulb. Repair or replace if necessary. Reconnect immobilizer unit connector, then return to Step 4.
8
  • Connect WDS or equivalent to DLC-2 and retrieve DTC.
  • Is following DTC displayed?
DTC P1602, P1603, P1604, P1621, P1622, P1624 		 Yes Go to appropriate DTC test.
No Go to next step.
9
  • Is there continuity between PCM ground terminals 6/22/23/25/100 and GND?
 Yes Go to next step.
No Repair or replace wiring harness.
10
  • Turn ignition key to ON (Engine OFF).
  • Inspect voltage between PCM terminals 34 and 60.
  • Is voltage above 11.5 V? 
 Yes Go to next step.
No Repair or replace wiring harness.
11
  • Disconnect immobilizer unit connector.
  • Turn ignition key to ON (Engine OFF)
  • Is there battery voltage at immobilizer unit connector terminal J?
 Yes Inspect for open circuit between PCM connector terminal 64 and immobilizer unit connector terminal A.
No Repair or replace wiring harness between immobilizer unit connector terminal J and fuse panel.
12
  • Verify following;
    • Vacuum connection
    • Air cleaner element
    • No air leakage from intake-air system
    • No restriction of intake-air system
    • Proper sealing of intake manifold and components attached to intake manifold: EGR valve, IAC valve
    • Ignition wiring
    • Fuel quality: proper octane, contamination, winter/summer blend
    • Electrical connections
    • Smooth operation of throttle valve
  • Are all items okay?
 Yes Go to next step.
No Service as necessary.
Repeat Step 12.
13
  • Turn ignition key to ON (Engine OFF)
  • Disconnect TP sensor connector.
  • Measure voltage at TP sensor connector VREF terminal with ignition key at ON.
Voltage 4.5-5.5 V 
  • Is voltage okay?
 Yes Go to next step.
No Go to troubleshooting "No.30 Constant voltage".
14
  • Connect WDS or equivalent to DLC-2.
  • Turn ignition key to ON (Engine OFF).
  • Retrieve any DTCs.
  • Is "PASSED" displayed?
 Yes No DTC is displayed: 
  • Go to next step.
No DTC is displayed: 
  • Go to appropriate DTC test.

Communication error message is displayed: 
  • Inspect for following:
    • Open circuit between main relay and PCM terminal 34 or 60
    • Open main relay GND circuit
    • Main relay is stuck open.
    • Open or poor GND circuit (PCM terminal 6,22, 23, 25 or 100)
    • Poor connection of vehicle body GND
15
  • Attempt to start engine at part throttle.
  • Does engine run smoothly at part throttle?
 Yes Inspect IAC valve and wiring harness.
No Go to next step.
16
  • Connect WDS or equivalent to DLC-2.
  • Access RPM PID.
  • Is RPM PID indicating engine speed during engine cranking?
 Yes Go to next step.
No Inspect for following:
  • Open or short circuit in CKP sensor
  • Open or short circuit between CKP sensor and PCM terminal 1 or 27
  • Open or short circuit in CKP sensor harnesses
    • If CKP sensor and harness are okay, go to next step.
17
  • Visually inspect CKP sensor and teeth of crankshaft pulley.
  • Are CKP sensor and teeth of crankshaft pulley okay?
 Yes Go to next step.
No Replace malfunctioning part.
18
  • Inspect ignition coil related harness condition (intermittent open or short) for all cylinders.
  • Are all harnesses condition okay?
 Yes Go to next step
No Repair suspected wiring harnesses.
19
  • Perform Spark Test. (See SPARK TEST .)
  • Is strong blue spark visible at all cylinder?
 Yes Go to next step.
  • If symptom occurs with A/C on, go to Step 15.
No Repair or replace malfunctioning part according to spark test results.
20
  • Inspect spark plug conditions.
  • Is spark plug wet, covered with carbon or grayish white?
 Yes Spark plug is wet or covered with carbon: 
  • Inspect for fuel leakage from injector.

Spark plug is grayish white: 
  • Inspect for clogged fuel injector.
No Install spark plugs on original cylinders.
Go to next step.
21
  • Remove and shake PCV valve.
  • Does PCV valve rattle?
 Yes Go to next step.
No Replace PCV valve.
22
  • Inspect for restriction in the exhaust system.
  • Is there any restriction?
 Yes Inspect exhaust system.
No Go to next step.
23
  • Install fuel pressure gauge between fuel filter and fuel distributor.
  • Connect jumper wire between F/P terminal at DLC in engine compartment and GND.
  • Turn ignition key to ON (Engine OFF).
  • Is fuel line pressure correct with ignition key at ON?
Fuel line pressure 420-460 kPa {4.3-4.6 kgf/cm2, 61-66 psi} 		 Yes Go to next step.
No Zero or low: 
  • Inspect fuel pump circuit.
  • Inspect for open fuel pump relief valve.
  • Inspect for fuel leakage inside pressure regulator.
  • Inspect for clogged, main fuel line.

High: 
  • Inspect pressure regulator for high pressure cause.
  • Inspect for clogged fuel return line.
24
  • Visually inspect for fuel leakage at fuel injector O-ring and fuel line.
  • Service as necessary.
  • Does fuel line pressure hold after ignition key is turned to OFF?
 Yes Go to next step.
No Inspect pressure regulator diaphragm condition.
  • If condition is okay, inspect fuel injector.
  • If condition is not okay, replace pressure regulator.
25
NOTE:
  • Following test is for stall concerns with A/C on. If other symptoms exist, go to next step.
  • Connect pressure gauges to A/C low and high pressure side lines.
  • Turn A/C on and measure low side and high side pressure.
  • Are pressures within specifications?

    (See REFRIGERANT PRESSURE CHECK .)

 Yes Go to next step.
No If A/C is always on, go to symptom troubleshooting "in NO.24 A/C ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY . For other symptoms, inspect following:
  • Refrigerant charging amount
  • Condenser fan operation
26
  • Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid side.
  • Plug opening end of vacuum hose.
  • Start engine.
  • Is engine stall now eliminated?
 Yes Inspect if purge solenoid valve is stuck open. Inspect EVAP control system.
No Go to next step.
27
  • Is air leakage felt or heard at intake-air system components while racing engine to higher speed?
 Yes Repair or replace.
No Go to next step.
28
  • Inspect engine condition while tapping EGR valve housing.
  • Does engine condition improve?
 Yes Replace EGR valve.
No Go to next step.
29 Yes Inspect valve timing.
No Inspect for cause.
30
  • Verify test results.
    • If okay, return to diagnostic index to service any additional symptoms.
    • If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
      • If vehicle is repaired, troubleshooting completed.
      • If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram PCM.
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