Diagnosis System

POWER STEERING: ELECTRONIC POWER STEERING SYSTEM: DIAGNOSIS SYSTEM

DIAGNOSIS SYSTEM

1. DESCRIPTION
(a) Connecting the Techstream to the vehicle and reading various data output from the power steering ECU assembly is the only difference between usual troubleshooting procedures and those for a vehicle with a diagnostic system.
The power steering ECU assembly records DTCs when the ECU detects a malfunction in the computer itself or in its circuits.
To check the DTCs, connect the Techstream to the DLC3. The Techstream enables you to erase the DTCs and check the freeze frame data and various forms of steering data.
2. CHECK DLC3





(a) Check the DLC3.
The power steering ECU assembly uses CAN and ISO 9141-2 as its communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.





HINT:
Connect the Techstream cable to the DLC3, turn the engine switch on (IG), and attempt to use the Techstream. If the screen displays a communication error message, a problem exists on the vehicle side or the Techstream side.
- If communication is normal when connecting the Techstream to another vehicle, inspect the DLC3 on the original vehicle.
- If communication is still not possible when connecting the Techstream to another vehicle, the problem is probably in the Techstream itself. Consult the Service Department listed in the Techstream's operator's manual.

3. P/S WARNING LIGHT





(a) Check that the PS warning light comes on when the engine switch is turned on (IG) and goes off in approximately 3 seconds.

(b) If the warning light does not come on or remains on, inspect the PS warning light circuit.