Honda Civic. Manual — part 513

NO -Replace the EPS control unit (see EPS CONTROL UNIT
REMOVAL/INSTALLATION ).

DTC 35-03: EPS CONTROL UNIT INTERNAL CIRCUIT (EPS CPU) (INITIAL DIAGNOSIS); DTC
35-05: EPS CONTROL UNIT INTERNAL CIRCUIT (MOTOR/EPS CPU) (INITIAL DIAGNOSIS)

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0).
3. Turn the ignition switch ON (II).

Does the EPS indicator come on?

YES -Go to step 4.

NO -Check for loose terminals or poor connections. If the connections are
good, the system is OK at this time.

4. Start the engine.
5. Wait 10 seconds or more.
6. Check for DTCs with the HDS.

Is DTC 35-03 or DTC 35-05 indicated?

YES -Check for loose terminals in the EPS control unit connectors, and repair
if necessary. If no poor connections are found, replace the EPS control unit
(see EPS CONTROL UNIT REMOVAL/INSTALLATION ).

NO -Troubleshoot the indicated DTC. If there are no DTCs, the system is OK
at this time.

DTC 51-01: LOW/HIGH VOLTAGE FOR THE TORQUE SENSOR (VT1 AND VT2) (REGULAR
DIAGNOSIS)

1. Turn the ignition switch to LOCK (0).
2. Connect the HDS to the data link connector (DLC).
3. Turn the ignition switch ON (II).
4. Check the ADVT1 in the DATA LIST with the HDS.

2008 Honda Civic EX

2006-08 STEERING EPS System - Civic (All Except Hybrid & Si)

Is the voltage at 0.90-3.55 V?

YES -Go to step 5.

NO -Go to step 6.

5. Check the ADVT2 in the DATA LIST with the HDS.

Is the voltage at 1.02-3.73 V?

YES -Check for loose wires or poor connections. If the connections are good,
the system is OK at this time.

NO -Go to step 6.

6. Turn the ignition switch to LOCK (0).
7. Disconnect EPS control unit connector D (28P).
8. Measure resistance between EPS control unit connector D (28P) terminals No.

9 and No. 10.

Fig. 32: Measuring Resistance Between EPS Control Unit Connector D
(28P) Terminals No. 9 And No. 10

Is the resistance between 12-15 ohms?

YES -Go to step 9.

NO -Go to step 13.

9. Measure resistance between EPS control unit connector D (28P) terminals No.

2008 Honda Civic EX

2006-08 STEERING EPS System - Civic (All Except Hybrid & Si)

8 and No. 9.

Fig. 33: Measuring Resistance Between EPS Control Unit Connector D
(28P) Terminals No. 8 And No. 9

Is the resistance between 12-15 ohms?

YES -Go to step 10.

NO -Go to step 15.

10. Check for continuity between EPS control unit connector D (28P) terminal No.

9 and body ground.

Fig. 34: Checking Continuity Between EPS Control Unit Connector D
(28P) Terminal No. 9 And Body Ground

Is there continuity?

YES -Go to step 11.

NO -Check for loose terminals in the EPS control unit connectors, and repair if

2008 Honda Civic EX

2006-08 STEERING EPS System - Civic (All Except Hybrid & Si)

necessary. If no poor connections are found, replace the EPS control unit (see
EPS CONTROL UNIT REMOVAL/INSTALLATION ).

11. Disconnect the torque sensor 3P connector from the steering gearbox.
12. Check for continuity between EPS control unit connector D (28P) terminal No.

9 and body ground.

Fig. 35: Checking Continuity Between EPS Control Unit Connector D
(28P) Terminal No. 9 And Body Ground

Is there continuity?

YES -Repair short to ground in the wire between the torque sensor and the
EPS control unit.

NO -Faulty torque sensor (short in the sensor internal circuit), replace the
steering gearbox (see STEERING GEARBOX REMOVAL AND
INSTALLATION ).

13. Disconnect the torque sensor 3P connector from the steering gearbox.
14. On the sensor side, measure the resistance between torque sensor terminals No.

1 and No. 2.

2008 Honda Civic EX

2006-08 STEERING EPS System - Civic (All Except Hybrid & Si)