Test Description
The number below refers to the step number on the diagnostic table.
- 3: This step verifies that the malfunction is present.
DTC P1404
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Is DTC P0641 also set? | - | Go to DTC P0641 or P0651 | Go to Step 3 |
| 3 |
|
1% | Go to Step 4 | Go to Step 6 |
| 4 |
|
10% | Go to Step 5 | Go to Step 7 |
| 5 |
|
- | Go to Step 6 | Go to Diagnostic Aids |
| 6 |
|
1% | Go to Step 7 | Go to Step 10 |
| 7 | Connect a test lamp between the 5-volt reference circuit of the EGR valve and the low reference circuit of the EGR valve. Does the test lamp illuminate? |
- | Go to Step 8 | Go to Step 9 |
| 8 | Connect a 3-amp fused jumper wire from the 5-volt reference circuit of the EGR valve to the EGR valve position signal circuit. Is the EGR Position Sensor parameter on the scan tool more than the specified value? |
99% | Go to Step 14 | Go to Step 12 |
| 9 | Connect a test lamp between the 5-volt reference circuit of the EGR valve and a good ground. Does the test lamp illuminate? |
- | Go to Step 11 | Go to Step 13 |
| 10 | Test the EGR valve position signal circuit for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 16 |
| 11 | Test the low reference circuit of the EGR valve for an open or for high resistance. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 16 |
| 12 | Test the EGR valve position signal circuit for high resistance or for a short to ground. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 16 |
| 13 | Test the 5-volt reference circuit of the EGR valve for an open or for high resistance. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 15 |
| 14 | Test for an intermittent and for a poor connection at the EGR valve. Refer to Testing for Intermittent Conditions and Poor Connections
and Repairing Connector Terminals
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 17 |
| 15 | Test all 5-volt reference circuits for a short to voltage. Refer to Testing for Intermittent Conditions and Poor Connections
and Repairing Connector Terminals
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 16 |
| 16 | Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections
and Repairing Connector Terminals
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 18 |
| 17 | Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement
. Did you complete the replacement? |
- | Go to Step 19 | - |
| 18 | Replace the ECM. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
- | Go to Step 19 | - |
| 19 |
|
- | Go to Step 2 | Go to Step 20 |
| 20 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK |