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DTC P1402: EGR Function: Procedure

  1. Inspect vacuum hoses for leaks, blockage or misrouting. See VACUUM DIAGRAMS article. Repair as necessary and retest system. If vacuum hoses are okay, turn ignition off. Disconnect ECM harness connector. See Figure. Turn ignition on. Connect a jumper wire between engine ground and ECM harness connector terminal No. 10. See Figure. If EGRC solenoid clicks when connecting and disconnecting jumper wire, go to next step. If EGRC solenoid does not click, repair EGRC solenoid or circuit. See DTC P1400: EGRC SOLENOID .
  2. Remove EGRC solenoid. See Figure. Using jumper wires, apply battery voltage between EGRC solenoid terminals. See Figure. Air should flow between ports "A" and "B". Air should not flow between ports "A" and "C". Remove jumper wires. Air should not flow between ports "A" and "B". Air should flow between ports "A" and "C". EGRC solenoid should switch in one second or less. If operation is as specified, go to next step. If operation is not as specified, replace EGRC solenoid and retest system.
  3. Check EVAP canister. See SYSTEM & COMPONENT TESTING article. Replace, if necessary and retest system. If EVAP canister is okay, check EVAP system vacuum hoses for leaks, blockage or misrouting. See VACUUM DIAGRAMS article. Repair as necessary and retest system. If vacuum hoses are okay, go to next step.
  4. Remove EGRC-BPT. Plug one vacuum port and apply vacuum to other vacuum port. Vacuum should not hold. Apply 3.94 in. H2 O (.98 kPa) of pressure to backpressure port. Vacuum should hold. If operation is as specified, go to next step. If operation is not as specified, replace EGRC-BPT and retest system.
  5. Remove EGR valve. Using a hand vacuum pump, apply vacuum to EGR valve. EGR valve should open. Release vacuum. EGR valve should close without sticking. If operation is as specified, go to next step. If operation is not as specified, clean or replace EGR valve and retest system.
  6. Remove EGR temperature sensor. See Figure. Measure resistance between EGR temperature sensor terminals, with EGR temperature sensor at specified temperatures. See EGR TEMPERATURE SENSOR RESISTANCE  table. If resistance is as specified, go to next step. If resistance is not as specified, replace EGR temperature sensor and retest system.
  7. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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