P1402
DTC P1402 EGR FUNCTIONDescription
SYSTEM DESCRIPTION
This system cuts and controls vacuum applied to the EGR valve to suit engine operating conditions. This cut-and-control operation is accomplished through the ECM and the EGRC-solenoid valve. When the ECM detects any of the following conditions, current through the solenoid valve is cut. This causes the vacuum to be cut. The EGR valve remains closed.
- Low engine coolant temperature
- Engine starting
- High-speed engine operation
- Engine idling
- Excessively high engine coolant temperature
- Mass air flow sensor malfunction
COMPONENT DESCRIPTION
Exhaust Gas Recirculation (EGR) Valve
The EGR valve controls the amount of exhaust gas routed to the intake manifold. Vacuum is applied to the EGR valve in response to throttle valve opening and EGRC-BPT valve operation. The vacuum controls the movement of a taper valve connected to the vacuum diaphragm in the EGR valve.
EGRC-solenoid Valve
The EGRC-solenoid valve responds to signals from the ECM. When the ECM sends an ON (ground) signal, the coil in the solenoid valve is energized. Vacuum signal (from the intake manifold collector) passes through the solenoid valve. The signal then reaches the EGR valve.
When the ECM sends an OFF signal, a plunger will then move to cut the vacuum signal from the intake manifold collector to the EGR valve.
On Board Diagnosis Logic
On Board Diagnosis Logic:
If EGR temperature sensor detects EGR flow under the condition that does not call for EGR, a high-flow malfunction is diagnosed.
NOTE: Diagnosis for this DTC will occur when engine coolant temperature is approx. 50 - 60 °C (122 - 140 °F). Therefore, it will be better to turn ignition switch "ON" (Start engine) at the engine coolant temperature below 40 °C (104 °F) when starting DTC confirmation procedure.
DTC Confirmation Procedure
NOTE: If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 5 seconds before conducting the next test.
TESTING CONDITION:
- Engine coolant temperature and EGR temperature must be verified in "DATA MONITOR" mode with CONSULT-II before starting DTC WORK SUPPORT test. If it is out of range below, the test cannot be conducted.
COOLAN TEMP/S: -10 to 40 °C (14 - 104 °F)*
EGR TEMP SEN: Less than 4.8 V
If the values are out of the ranges indicated above, park the vehicle in a cool place and allow the engine temperature to stabilize. Do not attempt to reduce the engine coolant or EGR temperature with a fan or means other than ambient air. Doing so may produce an inaccurate diagnostic result.
*: Although CONSULT-II screen displays -10 to 40 °C (14 - 104 °F) as a range of engine coolant temperature, ignore it.
WITH CONSULT-II
1. Turn ignition switch OFF and wait at least 5 seconds, then turn ignition switch ON.
2. Select "EGR SYSTEM P1402" of "EGR SYSTEM" in "DTC WORK SUPPORT" mode with CONSULT-II.
3. Touch "START". Follow instruction of CONSULT-II.
4. Start engine and let it idle until "TESTING" on CONSULT-II screen is turned to "COMPLETED". (It will take 60 seconds or more.)
If "TESTING" is not displayed after 5 minutes, turn ignition OFF and cool the engine coolant temperature to the range of -10 to 40 °C (14 - 104 °F). Retry from step 1.
5. Make sure that "OK" is displayed after touching "SELF-DIAG RESULTS". If "NG" is displayed, Refer to "Diagnostic Procedure" below.
WITH GST
1. Turn ignition switch ON and select MODE 1 with GST.
2. Check that engine coolant temperature is within the range of -10 to 40 °C (14 - 104 °F).
3. Check that voltage between ECM terminal 63 (EGR temperature sensor signal) and ground is less than 4.8 V.
4. Start engine and let it idle for at least 60 seconds.
5. Stop engine.
6. Perform from step 1 to 4.
7. Select MODE 3 with GST.
8. If 1st trip DTC is detected, Go to "Diagnostic Procedure" below.
Wiring Diagram
EC-EGRC1-01:
Diagnostic Procedure
Diagnostic Procedure (Steps 1 - 4):
Diagnostic Procedure (Steps 5 - 9):
Diagnostic Procedure (Step 10):
Component Inspection
EGR VALVE
1. Apply vacuum to EGR vacuum port with a hand vacuum pump.
EGR valve spring should lift.
2. Check for sticking.
3. If NG, repair or replace EGR valve.
EGRC-BPT VALVE
1. Plug one of two ports of EGRC-BPT valve.
2. Vacuum from the other port and check for leakage while applying a pressure above 0.981 kPa (100 mmH2O, 3.94 inH2O) from under EGRC-BPT valve.
3. If a leakage is noted, replace the valve.