Circuit Description
The DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance monitors EGR valve movement. The EGR valve position sensor is monitored by the powertrain control module (PCM). The 5-volt reference circuit, low reference circuit and the EGR valve position signal circuit are used by the PCM to determine the EGR valve position. The PCM compares the EGR Position Sensor parameter with the desired EGR Position parameter when the valve is commanded open or closed. If the PCM detects a calibrated difference between the EGR Position Sensor parameter and desired EGR Position parameter for a calibrated amount of time, this DTC sets.
DTC Descriptors
This diagnostic procedure supports the following DTC.
DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance
Conditions for Running the DTC
| • | DTC P0030, P0050, P0107, P0108, P0112, P0113, P0117, P0118, P0135, P0155, P0335, P0336, P0401, P0403, P0406, P0641, P0651, P1128, P1129, P2413, P2414, and P2415 are not set. |
| • | The battery voltage is at least 10.5 volts |
| • | The EGR valve is commanded open to at least 0.25 mm (0.010 in). |
| • | Engine speed is less than 4,000 RPM. |
| • | DTC P0404 runs once per drive cycle once the above conditions have been met. |
Conditions for Setting the DTC
| • | The difference between the desired EGR position and the measured EGR position, as determined by the EGR position sensor, is more than 1.020 mm (0.041 in). |
| • | The above condition is present for more than 5 seconds |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
| • | Inspect for excessive deposits on the EGR pintle or seat. Inspect for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick. |
| • | If the condition is intermittent, refer to Intermittent Conditions . |
Test Description
The number below refers to the step number on the diagnostic table.
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This step tests for high resistance in reference voltage circuit. If the test lamp does not illuminates at all, there is excessive resistance in the 5-volt reference circuit or low reference ground circuit.
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This step tests for high resistance in the EGR solenoid control circuit and ground circuits. The PCM provides a 12 volt bias signal on the solenoid control circuit that is pulled low when the solenoid is OK and has a good ground. If the circuit resistance is OK, the DMM should measure ignition voltage.
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After replacing the PCM a new minimum throttle position and idle speed must be established.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||
2 | Is DTC P0403 or P0406 also set? | -- | Go to Step 3 | |||||||
3 |
Was the EGR Sensor voltage within the first specified value when at 50 percent and within the second specified value when at 100 percent? | 2.10-2.20 V 3.10-3.20 V | Go to Step 4 | Go to Step 5 | ||||||
4 |
Did the DTC fail this ignition? | -- | Go to Step 5 | Go to Diagnostic Aids | ||||||
Does the test lamp illuminate at least dimly? | -- | Go to Step 6 | Go to Step 7 | |||||||
6 |
Is the EGR sensor voltage near the specified value? | 4.96 V | Go to Step 8 | Go to Step 12 | ||||||
7 | Connect the test lamp between the 5-volt reference circuit of the EGR valve and a good ground. Does the test lamp illuminate at least dimly? | -- | Go to Step 11 | Go to Step 13 | ||||||
Is the voltage near the specified value? | 12 V | Go to Step 10 | Go to Step 9 | |||||||
9 | Connect the DMM between the EGR solenoid control circuit and a known good ground. Is the voltage near the specified value? | 12 V | Go to Step 15 | Go to Step 14 | ||||||
10 |
Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 16 | ||||||
11 | Test the low reference circuit of the EGR position sensor for high resistance. Refer to Exhaust Gas Recirculation Valve Replacement Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 17 | ||||||
12 | Test the EGR position sensor signal circuit for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 17 | ||||||
13 |
Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 17 | ||||||
14 | Test the control circuit of the EGR valve for resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 17 | ||||||
15 | Repair the condition of high resistance in the ground circuit of the EGR valve. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 20 | -- | ||||||
16 | Test for an intermittent and for a poor connection at the EGR valve. Refer to Testing for Intermittent Conditions and Poor Connections Connector Repairs and in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 18 | ||||||
17 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19 | ||||||
18 | Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Did you complete the replacement? | -- | Go to Step 20 | -- | ||||||
Did you complete the replacement? | -- | Go to Step 20 | -- | |||||||
20 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 21 | ||||||
21 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||
