Diagnosis & Repair Procedure
NOTE:
For better performance and results of this diagnostic procedure, usage of appropriate wiring diagram is recommended. See ENGINE PERFORMANCE
in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
NOTE:
Perform all voltage and resistance tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use an ohmmeter to isolate wiring harness shorts or opens.
- If engine system check has been performed, go to next step. If engine system check has not been performed, perform TEST D: ENGINE SYSTEM CHECK under SYSTEM TESTS, then go to next step.
- Using scan tool, check for current or pending DTC P2227. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If DTC P2227 is set, go to next step. If DTC P2227 is not set, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .
- Turn ignition switch to LOCK position. Disconnect ECM harness connectors C45and C46. See Figure. Turn ignition switch to ON position. Measure voltage between ECM harness connectors C45 terminal No. 7 (Light Green/Red wire) and C46 terminal No. 27 (Orange wire). See Figure. Voltage should be as indicated in TESTING MAP SENSOR VOLTAGE table. If voltage is not as specified, check MAP sensor system and component, referring to DTC P0107: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT - LOW INPUT or DTC P0108: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT - HIGH INPUT
. If voltage is as specified, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .TESTING MAP SENSOR VOLTAGE
Condition Altitude Voltage Key ON, Engine OFF 0-2000 Ft. 3.3-4.3Volts Key ON Engine Running 0-2000 Ft. 0.7-1.6 Volts