Trouble Code E.7.8
Power steering pressure switch circuit sends 12 volt signal to ECM, except when power steering load is applied. When power steering load is applied, power steering cut-off switch is opened and power steering anticipate signal drops to 0 volts.
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- Code indicates that power steering anticipate signal does not switch from 12 to 0 volts when power steering load is applied. To begin diagnosis, disconnect power steering cut-off switch, then reconnect switch to verify proper operation. If code has passed, check for faulty power steering cut-off switch. If code did not pass, install jumper across harness at power steering cut-off switch. If code has now passed, then check for open power steering cut-off switch connector or open power steering cut-off switch.
- If code did not pass with jumper across harness connector, use test light to test continuity of circuit No. 639. If test light does not light, check for blown solenoid fuse. If fuse is blown, check for short to ground in circuit Nos. 639 or 495. If solenoid fuse is not blown, check for open in circuit No. 639.
- If test light to ground on circuit No. 639 lights, probe pin 6 of Orange ECM connector with test light to 12 volts to determine if ECM can recognize 12 volt signal. Center terminal of lighter harness connector is a convenient source of 12 volts. If code has not passed, check for faulty ECM connector or faulty ECM. If code has passed, check for open in circuit No. 495. If no open is present, check for faulty power steering cut-off switch connection.