Power Steering System Troubleshooting & Testing: Other Honda Civic IX

EPS Indicator

Under normal conditions, the EPS indicator (A) comes on when the ignition switch is turned to ON (II), then goes off after the engine is started. This indicates that the LED and its circuit are operating correctly.

If there is a failure in the system after the engine is started, the EPS indicator will stay on, and the power assist is turned off or restricted.

Scheme 108

When the EPS indicator comes on, the control unit stores the DTC. In this case, the control unit will not activate the EPS system after the engine starts again, but it keeps the EPS indicator on.

The EPS indicator will stay on until the DTC is erased. When a problem is detected and the EPS indicator comes on, there are cases when the indicator stays on until the ignition switch is turned to LOCK (0), and cases when the indicator goes off automatically when the system returns to normal. Even though the system is operating normally, the EPS indicator will come on under some conditions with the vehicle stopped and the engine at high speed with constant input from the steering wheel.

To determine the actual cause of the problem, question the customer about the conditions during which the problem occurred, taking the above conditions into consideration.

Steering Angle Sensor Neutral Position

The EPS control unit stores the steering angle sensor neutral position in the EEPROM. The steering angle sensor neutral position must be memorized whenever the steering gearbox is replaced or if the front toe is adjusted.

How to Retrieve DTCs

1. With the ignition switch in LOCK (0), connect the HDS to the data link connector (DLC) located under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the EPS control unit. If it does not, go to the DLC circuit troubleshooting See DLC CIRCUIT TROUBLESHOOTING (EXCEPT K24Z7) or DLC CIRCUIT TROUBLESHOOTING (K24Z7) .
4. Follow the prompts on the HDS to display the DTC(s) on the screen. After determining the DTC, refer to the DTC troubleshooting. Do the all systems DTC check, and troubleshoot any powertrain DTCs first.
5. Turn the ignition switch to LOCK (0).

How to Clear DTCs

1. With the ignition switch in LOCK (0), connect the HDS to the data link connector (DLC) located under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the EPS control unit. If it does not, go to the DLC circuit troubleshooting See DLC CIRCUIT TROUBLESHOOTING (EXCEPT K24Z7) or DLC CIRCUIT TROUBLESHOOTING (K24Z7) .
4. Clear the DTC(s) by following the screen prompts on the HDS.
5. Turn the ignition switch to LOCK (0).

Scheme 109

1. Power Steering Assist Check NOTE: This test should be done with original equipment tires and wheels at the correct tire pressure. Start the engine, and let it idle. Attach a commercially available spring scale (A) to the steering wheel. With the engine idling and the vehicle on a clean, dry floor, pull the scale as shown, and read it as soon as the tires begin to turn. Initial turning load: 34 N (3.5 kgf, 7.6 lbf) If the scale reads no more than the specification, the power assist is OK. If it reads more, check these items: Steering linkage Rack guide adjustment EPS system