ENGINE (DIAGNOSTICS)(H4DO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)
DTC P1492 COIL 1 EGR "A" CONTROL CIRCUIT LOW
NOTE:
For the diagnostic procedure, refer to DTC P1498. Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P1498 COIL 4 EGR "A" CONTROL CIRCUIT LOW">
1. OUTLINE OF DIAGNOSIS
• Detects open or short circuit of EGR.
• Judge as NG when the ECM output level differs from the actual terminal level.
2. COMPONENT DESCRIPTION

(1) | Engine control module (ECM) | (4) | Switch circuit | (6) | Main relay |
(2) | Computer unit (CPU) | (5) | Battery voltage | (7) | EGR control valve |
(3) | Detecting circuit |
3. EXECUTION CONDITION
Secondary Parameters | Execution condition |
Battery voltage | ≥ 10.9 V |
EGR control signal | OFF |
4. GENERAL DRIVING CYCLE
Perform diagnosis continuously during EGR operation.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Malfunction Criteria | Threshold Value |
EGR control voltage | ≤ Battery voltage ? 0.34 V |
Time Needed for Diagnosis: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
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