Note. Without ECU test harness, backprobing with voltmeter would do but take care not to damage wires and you might need to remove the ECU from the support cover.
CODE 7 - THROTTLE ANGLE SENSOR
1. Turn ignition off. Remove appropriate fuse for 10 seconds to reset ECU. Start engine. Verify if CHECK ENGINE light is on and if LED is flashing Code 7. If Code 7 is present, go to next step. If Code 7 is not present, problem is intermittent. Check connectors at throttle angle sensor and related circuits.
2. Turn ignition off. Disconnect 3-wire connector at throttle angle sensor. Turn ignition on. Measure voltage between Yellow/White (+) and Green/White (-) wires. If voltage is not about 5 volts, go to step 6). If voltage is about 5 volts, turn ignition off. Reconnect sensor connector. Connect ECU Test Harness between ECU and ECU connector.
3. Turn ignition on. Apply 20 in. Hg to throttle dashpot diaphragm. Measure voltage between positive terminal C7 and negative terminal C12. See Fig. 3 .Voltage should be .5 volt at closed throttle and about 4.5 volts at wide open throttle. Transition between lower and upper voltage specification as throttle is depressed should be smooth.
4. If throttle sensor responds as indicated, substitute a known good ECU. If condition is corrected, replace original ECU. If sensor does not respond as indicated in step 3), replace throttle sensor or repair open or short in Red/Blue wire between ECU terminal C7 and throttle sensor.
5. If voltage reading between Yellow/White (+) and Green/White (-) wires in step 2) is not about 5 volts, measure voltage between ground and Yellow/White wire terminal. If voltage is now about 5 volts, repair open in Green/White wire between ECU terminal C12 and throttle sensor. If reading is not about 5 volts, turn ignition off.
6. Connect ECU Test Harness between ECU and ECU connector. Turn ignition on. Measure voltage between terminal C13 and terminal C12. If voltage is about 5 volts, repair open Yellow/White wire between ECU terminal C13 and throttle sensor. If reading is not about 5 volts, substitute a known good ECU. If condition is corrected, replace original ECU.
Code 21 = VTEC Spool valve
Code 22 = VTEC Oil presure switch
Tuesday, February 24th, 2009 AT 12:02 PM