Diagnosis & Repair
- Connect scan tool to DLC No. 3 connector. See Fig 1. Turn ignition on. Using scan tool, read MAP sensor value. If reading is same as atmospheric pressure, go to next step. If reading in not same as atmospheric pressure, check component and ECM connections. Problem is intermittent.
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- Access ECM behind glove box. Turn ignition on. Backprobing ECM connector, measure voltage between terminals No. 9 (Brown wire) and No. 11 (Light Green/Red wire) at ECM E6 connector. See Fig 2. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, replace ECM and retest.
- Backprobing ECM connector, measure voltage between terminals No. 2 (Pink wire) and No. 11 (Brown wire) at ECM E6 connector. If voltage is 3.3-3.9 volts, replace ECM and retest. If voltage is not 3.3-3.9 volts, go to next step.
- Check for open or short circuit in wiring harness between MAP sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS
article. Repair wiring as necessary. If wiring harness is okay, replace MAP sensor and retest.
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