KA1 - Enter Output State Check

DTC 558 indicates a failure in the EVR solenoid circuit.

Possible causes:

- Damaged EVR solenoid.

- Damaged vacuum hose(s).

- Open in harness.

- Short in harness.

- Damaged PCM.

NOTE: Do not use STAR Tester for this step. Use a VOM/DVOM.

- Key "OFF".

- Disconnect electrical connector on the speed control servo, if equipped.

- DVOM on 20 volt scale.

- Connect DVOM negative test lead to STO circuit at Data Link Connector (DLC) and positive test lead to battery positive.

- Jumper STI circuit to SIG RTN at the DLC.

- Perform Key On Engine Off (KOEO) Self-Test until the completion of the Continuous Test DTCs.

- DVOM will indicate less than 1.0 volt when test is completed.

- Depress and release the throttle.

- Does voltage increase?

Yes -- Remain in Output State Test Mode. Go to KA2. KA2 - Check EVR Solenoid Electrical Operation

No -- Depress throttle to WOT and release. If STO voltage does not go high leave equipment hooked up and go to QC1. QC1 - Check For Codes 23, 53, 63, 121, 122 or 123