Ignition Signal Test - Code 21
- Disconnect 20-pin connector and check for insulation between terminals No. 3, 5 and 14 and ground. See Fig 1 . If there is no continuity, repair harness.
- If there is continuity, check power transistor. With ohmmeter positive lead on terminals No. 1, 4, 4 and 2, continuity should be found at terminals No. 5, 2, 3 and 3 respectively. See Fig 1 . If checks are okay, perform ECCS self-diagnosis procedure. If okay, end test. If not okay, replace ECCS control unit.
- If voltage was present, check harness between ECU and power transistor. Disconnect ECU 20-pin connector and check for insulation between terminals No. 3, 5 and ground. No resistance should exist. Place a lead wire across terminals No. 3 and 2 of harness connector, and measure resistance between terminals No. 3 and 5 in 20-pin connector. If no resistance is found, repair or replace harness.
- If resistance was found, check power transistor for continuity. Refer to the POWER TRANSISTOR CONTINUITY VALUES table for Maxima readings.
POWER TRANSISTOR CONTINUITY VALUES
| Tester Terminal (+ / -) | Continuity |
|---|---|
| 1/2 | Yes |
| 1/3 | Yes |
| 1/4 | Yes |
| 2/1 | No |
| 2/3 | No |
| 2/4 | Yes |
| 3/1 | Yes |
| 3/2 | Yes |
| 3/4 | Yes |
| 4/1 | No |
| 4/2 | Yes |
| 4/3 | No |