P0201
Injector Circuit:
Connectors: A-21X, B-01, B-02, B-05, B-06, B-25, B-26, B-48, C-51 <M/T>, C-52 <A/T>:
CIRCUIT OPERATION
- The injector power is supplied from the MFI relay (terminal 1).
- The ECM
TECHNICAL DESCRIPTION
- The amount of fuel injected by the injector is controlled by the amount of continuity time the coil is grounded by the ECM
- A surge voltage is generated when the injectors are driven and the current flowing to the injector coil is shut off.
- The ECM
DTC SET CONDITIONS
Check Area
- Engine speed is lower than 1,000 r/min.
- Throttle position sensor output voltage is lower than 1.16 volts.
Judgment Criteria
- Injector coil surge voltage (battery positive voltage +2 volts) has not been detected for two seconds.
TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Injector failed.
- Open or shorted injector circuit, or loose connector.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tool:
MB991348: Test Harness
MD998464: Test Harness
STEP 1. Check the left bank injector.
1. Disconnect the left bank injector connector.
2. Measure the resistance between each injector side connector terminals 1 and 2.
Standard value: 13 - 16 ohms [at 20°C (68°F)]
If within specifications, go to Step 2.
If not within specifications, replace the injector. Then go to Step 12.
STEP 2. Check injector intermediate connector B-48 at the right bank injector.
1. Disconnect the injector intermediate harness connector.
2. Measure the resistance between injector side connector terminals 1 and 2 (No.1 injector), 1 and 3 (No.3 injector), 1 and 4 (No.5 injector).
Standard value: 13 - 16 ohms [at 20°C (68°F)]
If within specifications, go to Step 5.
If not within specifications go to Step 3.
STEP 3. Check the right bank injector.
1. Remove the intake manifold.
2. Disconnect the injector connector deviated from the standard value in Step 2.
3. Measure the resistance between injector side connector terminals 1 and 2.
Standard value: 13 - 16 ohms [at 20°C (68°F)]
If within specifications, go to Step 4.
If not within specifications, replace the injector. Then go to Step 12.
STEP 4. Check harness connector B-01 or B-05 or B-26 at the right bank injector for damage.
1. Check the injector connector deviated from the standard value in Step 2.
If the connector is in good condition, repair the harness wire between the injector connector and injector intermediate harness connector. Then go to Step 12.
If the connector is damaged, repair or replace it.
Refer to Harness Connector Inspection. Then go to Step 12.
STEP 5. Check the power supply line at the left bank injector connectors B-02, B-06, B-25.
1. Disconnect connectors B-02, B-06, B-25 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 1 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to "LOCK" (OFF) position. If within specifications, go to Step 6.
If not within specifications, repair the harness wires between the MFI relay connector A-21X and the injector connectors B-02, B-06, B-25. Then go to Step 12.
STEP 6. Check harness connector B-02, B-06, B-25 at the left bank injector for damage.
If harness connectors B-02, B-06, B-25 are in good condition, go to Step 7.
If harness connectors B-02, B-06, B-25 are damaged, repair or replace them.
Refer to Harness Connector Inspection. Then go to Step 12.
STEP 7. Check the power supply line at injector intermediate connectors B-48.
1. Disconnect connector B-48 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 1 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to "LOCK" (OFF) position.
If within specifications, go to Step 8.
If not within specifications, repair the harness wires between the MFI relay connector A-21X and the injector intermediate connector B-48. Then go to Step 12.
STEP 8. Check intermediate injector connector B-48 for damage.
If connector B-48 is in good condition, go to Step 9.
If connector B-48 is damaged, repair or replace it.
Refer to Harness Connector Inspection. Then go to Step 12.
STEP 9. Check the circuits at ECM connector C-51
1. Disconnect connector C-51
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminals 1, 2, 9, 10, 24, 25 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to "LOCK" (OFF) position.
If within specifications, go to Step 10.
If not within specifications, repair the harness wires between the injector B-01, B-02, B-05, B-06 B-25, B-26 and the ECM connector C-49
STEP 10. Check harness connector C-51 at the ECM
If harness connector C-51
If harness connector C-51
Refer to Harness Connector Inspection. Then go to Step 12.
STEP 11. Using the analyzer, check the injector.
1. Check the right bank side injectors (No.1. No.3, No.5), as follows:
a. Disconnect injector intermediate connector B-48 and connect the test harness special tool (MD998464) in between.
b. Connect the analyzer special patterns pickup to each injector intermediate connector terminal to analyze each cylinder.
- Terminal 2 (black clip of the special tool) for the number 1 cylinder
- Terminal 3 (blue clip) for the number 3 cylinder
- Terminal 4 (white clip) for the number 5 cylinder
2. Check the left bank side injectors (No.2, No.4, No.6), as follows:
a. Disconnect injector connectors B-02, B-21, B-25 and connect the test harness special tool (MB991348) in between. (All terminals should be connected)
b. Connect the analyzer special patterns pickup to the injector side connector terminal 2.
NOTE: When measuring with the ECM or PCM side connector, connect an analyzer special patterns pickup to the each of the following terminals.
- PCM or ECM terminal I when measuring number 1 cylinder injector.
- PCM or ECM terminal 9 when measuring number 2 cylinder injector.
- PCM or ECM terminal 24 when measuring number 3 cylinder injector.
- PCM or ECM terminal 2 when measuring number 4 cylinder injector.
- PCM or ECM terminal 10 when measuring number 5 cylinder injector.
- PCM terminal 25 when measuring number 6 cylinder injector.
3. Start the engine and run at idle.
4. Measure the waveform.
- The waveform should show a normal pattern similar to the illustration.
5. Turn the ignition switch to "LOCK" (OFF) position. If the waveform shows a normal pattern, it can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope With Intermittent Malfunction.
If the waveform does not show a normal pattern, replace the ECM or PCM. Then go to Step 12.
STEP 12. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Procedure 6 - Other Monitor.
2. Read the diagnostic trouble code, and confirm that diagnostic trouble codes P0201, P0202, P0203, P0204, P0205, P0206 does not reset.