DTC P0551: POWER STEERING SWITCH FAILURE Jeep Cherokee II рестайлинг

Note. For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.

Note. DTC P0551: POWER STEERING SWITCH FAILURE is monitored with engine running. DTC may be stored in Powertrain Control Module (PCM) if PCM senses Power Steering (P/S) pressure switch remains open with vehicle speed more than 40 MPH for more than 30 seconds. Possible causes are: defective P/S pressure switch, defective PCM, defective connector or defective wiring.

1. Start engine and allow it to idle. Using scan tool, monitor P/S pressure switch state. Turn steering wheel to extreme left and right. If P/S pressure switch state changes, go to next step. If P/S pressure switch state does not change, go to step 4).
2. Ensure engine is still idling Using scan tool, monitor P/S pressure switch state while wiggling wiring harness from P/S pressure switch to PCM. P/S pressure switch is attached to power steering high pressure hose at pump. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. If P/S pressure switch state changes while wiggling wiring harness, repair wiring harness where wiggling caused P/S pressure switch state to change. Perform TEST VER-5A. If P/S pressure switch state does not change, go to next step.
3. Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. Perform TEST VER-5A. If connectors and wiring harness are okay, test is complete.
4. Ensure ignition is off. Disconnect P/S pressure switch connector. P/S pressure switch is attached to power steering high pressure hose at pump. Clean and/or repair connector as necessary. Connect one end of a jumper wire to P/S pressure switch connector, switch sense circuit (Dark Blue/Brown wire). Turn ignition on, with engine off. Using scan tool, monitor P/S pressure switch . Touch other end of jumper wire to ground 5 times. If P/S pressure switch state changes, go to next step. If P/S pressure switch state does not change, go to step 7).
5. Turn ignition off. Ensure P/S pressure switch connector is still disconnected. Using an ohmmeter, check resistance between ground and P/S pressure switch connector, ground circuit (Black wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open ground circuit. Perform TEST VER-5A.
6. At this time, P/S pressure switch is assumed to be defective. Replace P/S pressure switch. Perform TEST VER-5A.
7. Ensure ignition is off. Ensure P/S pressure switch connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance between ground and P/S pressure switch connector, switch sense circuit (Dark Blue/Brown wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair switch sense circuit for short to ground. Perform TEST VER-5A.
8. Ensure ignition is off. Ensure P/S pressure switch and PCM connectors are still disconnected. Using ohmmeter, check resistance of P/S pressure switch sense circuit (Dark Blue/Brown wire) between PCM and P/S pressure switch connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open P/S pressure switch sense circuit. Perform TEST VER-5A.
9. At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-5A.