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NO.5 ENGINE STALLS-AFTER START/AT IDLE [WITH WU-TWC]

id0103008011c5

5 | ENGINE STALLS-AFTER START/AT IDLE
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DESCRIPTION | • The engine stops unexpectedly.
POSSIBLE CAUSE | • A/C system operation is improper • Air leakage from intake-air system parts • Purge solenoid valve malfunction • Improper operation of IAC valve • EGR valve malfunction (ZJ) • No signal from CKP sensor due to sensor, related wiring harness or wrong installation • Vacuum leakage • Engine overheating • Low engine compression • Erratic signal to ignition coil • Poor fuel quality • PCV valve malfunction • Air cleaner restriction • Restriction in exhaust system • Electrical connector disconnection • Open or short circuit in fuel pump body and related wiring harness • No battery power supply to PCM or poor ground • Inadequate fuel pressure • Fuel pump body mechanical malfunction • Fuel leakage from fuel injector • Fuel injector clogging • Ignition coil malfunction • Improper air/fuel mixture ratio control • Improper valve timing • Improper operation variable valve timing control system • Immobilizer system (PATS) and/or circuit malfunction (if equipped) • Pressure regulator malfunction Warning The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: • Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. • Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. Caution • If there is foreign material on the connecting area of the quick release connector, it might damage the connector or the fuel pipe. To prevent this, disconnect the connector and clean the connecting area before connecting.

Diagnostic procedure

STEP | INSPECTION | RESULTS | ACTION
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1 | Note • The following test should be performed for vehicles with an immobilizer system. Go to Step 10 for vehicles without an immobilizer system. Connect the WDS or equivalent to the DLC-2. Do the following conditions appear? • The engine does not completely start. • DTC B1681 is displayed. | Yes | Both conditions appear: Go to Step 3.
No | Either condition appears: Go to the next step.
2 | Does the engine stall after approx. 2 s often the engine is started? | Yes | Go to the next step.
No | The immobilizer system is normal. Go to Step 10.
3 | Is the coil connector securely connected to the coil? | Yes | Go to the next step.
No | Connect the coil connector securely. Return to Step 2.
4 | Does the security light illuminate? | Yes | Go to the next step.
No | Inspect the instrument cluster and wiring harness.
5 | Connect the WDS or equivalent to the DLC-2 and retrieve any DTCs. Are any of following DTCs displayed? DTC B1213, B1342, B1600, B1602, B1681, B2103, B2431 | Yes | Go to the appropriate DTC test.
No | Go to the next step.
6 | Is there continuity between the PCM ground terminals 2AZ, 2BH, 2BD, and ground? | Yes | Go to the next step.
No | Repair or replace the wiring harness.
7 | Measure voltage between the PCM ground terminals 2AZ, 2BH, 2BD, and coil terminal C. Is the voltage 1.0 V or less? | Yes | Go to the next step.
No | Repair or replace the wiring harness.
8 | Turn the ignition switch to the ON position. Access VPWR PID. Is VPWR PID normal? VPWR PID Battery voltage | Yes | Go to the next step.
No | Repair or replace the wiring harness.
9 | Disconnect the coil connector. Turn the ignition switch to the ON position. Is there battery voltage at coil connector terminal D? | Yes | Inspect the following: • Open or short circuit between coil terminal A and PCM terminal 1AS • Open or short circuit between coil terminal B and PCM terminal 1AO
No | Repair or replace the wiring harness between the coil connector terminal D and fuse panel.
10 | Inspect the 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: IAC valve, EGR valve (ZJ) • Ignition wiring • Fuel quality: proper octane, contamination, winter/summer blend • Electrical connections • Smooth operation of throttle valve Are all items normal? | Yes | Go to the next step.
No | Service if necessary. Repeat Step 10.
11 | Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO, and KOER DTCs. (See KOEO/KOER SELF-TEST.) If the engine stalls, retrieve continuous memory and KOEO DTCs. Are any DTCs displayed? | Yes | DTC is displayed: Go to the appropriate DTC test. Communication error message is displayed: Inspect for the following: • Open circuit between the main relay and PCM terminal 1BF or 1BG • Open main relay ground circuit • The main relay is stuck open. • Open or poor ground circuit (PCM terminal 2BH, 2AZ or 2BD) • Poor connection of the vehicle body ground
No | No DTC is displayed: Go to the next step.
12 | Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle? | Yes | Inspect the IAC valve and wiring harness.
No | Go to the next step.
13 | Connect the WDS or equivalent to the DLC-2. Access the RPM PID. Is the RPM PID indicating engine speed when cranking the engine? | Yes | Go to the next step.
No | Inspect for the following: • Open or short circuit in CKP sensor • Open or short circuit between CKP sensor terminal A and PCM terminal 2T • Open or short circuit between CKP sensor terminal B and PCM terminal 2P • Open or short circuit between CKP sensor terminal C and PCM terminal 2BF • Open or short circuit in CKP sensor harnesses If the CKP sensor and harness are normal, go to the next step.
14 | Visually inspect the CKP sensor and teeth of the crankshaft pulley. Are the CKP sensor and teeth of the crankshaft pulley normal? | Yes | Go to the next step.
No | Replace the malfunctioning parts.
15 | Measure the gap between the CKP sensor and teeth of crankshaft pulley. Specification 0.5-1.5 mm {0.02-0.05 in} Is the gap within specification? | Yes | Go to the next step.
No | Replace the plate.
16 | Inspect the ignition coil related harness condition (intermittent open or short) for all cylinders. Are harness conditions normal? | Yes | Go to the next step.
No | Repair suspected wiring harnesses.
17 | Carry out a spark test. Is a strong blue spark visible at each cylinder? | Yes | Go to the next step. If the symptom occurs with the A/C on, go to Step 23.
No | Repair or replace the malfunctioning part according to spark test result.
18 | Inspect the spark plugs. Is the spark plug wet, covered with carbon or grayish white? | Yes | Spark plug is wet or covered with carbon: Inspect for fuel leakage from the fuel injector. Spark plug is grayish white: Inspect for clogged a fuel injector.
No | Install the spark plugs on the original cylinders. Go to the next step.
19 | Remove and shake the PCV valve. Does the PCV valve rattle? | Yes | Go to the next step.
No | Replace the PCV valve.
20 | Visually inspect the exhaust system part. Is there any deformed exhaust system part? | Yes | Replace the suspected part.
No | Go to the next step.
21 | Install a fuel pressure gauge between the fuel pipe and the fuel distributor. Connect the WDS or equivalent to the DLC-2. Turn on the fuel pump using the FP PID in the output state control of the datalogger function. Is the fuel line pressure correct? | Yes | Go to the next step.
No | Zero or low: Inspect the fuel pump relay and the fuel pump related circuit. Inspect for fuel leakage inside the pressure regulator. Inspect for a clogged main fuel line. High: Inspect the pressure regulator for the cause of high pressure. Inspect for a clogged fuel return line. Inspect the vacuum hose to the pressure regulator.
22 | Visually inspect for fuel leakage at fuel injector O-ring and fuel line. Service if necessary. Is the fuel line pressure held after the FP PID is turned off? | Yes | Go to the next step.
No | Inspect the pressure regulator diaphragm. • If the condition is normal, inspect the fuel injector. • If the condition is not normal, replace the pressure regulator.
23 | Note • The following test is for stall concerns with the A/C on. If other symptoms exist, go to the next step. Connect pressure gauges to the A/C low and high pressure side lines. Turn the A/C on and measure the low side and high side pressures. Are the pressures within the specifications? | Yes | Go to the next step.
No | If the A/C is always on, go to symptom troubleshooting "No.24 A/C is always on or A/C compressor runs continuously". For other symptoms, inspect the following: • Refrigerant charging amount • Condenser fan operation
24 | Disconnect the vacuum hose between the purge solenoid valve and the intake manifold from the purge solenoid side. Plug the open end of the vacuum hose. Start the engine. Is the engine stall now eliminated? | Yes | Inspect if the purge solenoid valve sticks open. Inspect the evaporative emission control system.
No | Go to the next step.
25 | Is air leakage felt or heard at the intake-air system components while racing the engine to a higher speed? | Yes | Repair or replace.
No | Go to the next step. (with EGR system) Go to Step 27. (without EGR system)
26 | Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve? | Yes | Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [WITH WU-TWC].)
No | Go to the next step.
27 | Inspect variable valve timing control system operation. Does variable valve timing control function properly? | Yes | Go to the next step.
No | Repair or replace the malfunctioning parts.
28 | Is the engine compression correct? | Yes | With EGR system: Remove the EGR valve and visually inspect for a mechanically stuck EGR valve. • If there is no malfunction, inspect the valve timing. Without EGR system: Inspect the valve timing.
No | Inspect for the cause.
29 | Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, inspect related Service information and perform repair or diagnosis. - If the vehicle is repaired, the troubleshooting is completed. - If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.