Diagnosis & Repair
- Connect scan tester to DLC3 connector. See Figure. Turn ignition on. Turn scan tester on. Using scan tester read MAP sensor value. If reading is same as atmospheric pressure, go to next step. If reading in not same as atmospheric pressure, inspect component and ECM connections. Problem is intermittent.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Access ECM behind glove box. Turn ignition on. Backprobing ECM connector, measure voltage between terminals No. 18 (Light Green/Red wire) and No. 16 (Brown wire) at ECM E7 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. 4 (Pink wire) and No. 16 (Brown wire) at ECM E7 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 an open or short circuit between MAP sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS
article. Repair as necessary. If circuit is okay, replace MAP sensor and retest.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002