Honda ACCORD HYBRID 2005 Service Manual page 1250

EPS Components
G e n e r a l T r o u b l e s h o o t i n g I n f o r m a t i o n
EPS Indicator
Under normal conditions, the EPS indicator comes on
w h e n the ignition switch is turned to the ON (II) position,
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 w i l l stay o n , and the power
assist is turned off.
W h e n EPS indicator comes o n , the control unit
memorizes 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.
W h e n DTC 11, 12 or 13 is stored in the control unit, the
EPS indicator will stay on until the DTC is erased. W h e n
a p r o b l e m is detected and the EPS indicator comes o n ,
there are cases w h e n the indicator stays on until the
ignition switch is turned OFF, and cases w h e n the
indicator goes off automatically w h e n the system
returns to normal. Even t h o u g h the system is operating
normally, the EPS indicator w i l l c o m e on under the
f o l l o w i n g conditions:
• The vehicle speed decreases abruptly f r o m 12 m p h
(20 km/h) or more (by applying brake), and it is less
than 1 m p h (1 km/h) and engine speed is 2,000 r p m or
above for 5 seconds (continuously) after the abrupt
deceleration.
• W h i l e turning the steering wheel w i t h the vehicle
speed of 1 m p h (1 km/h) or less for 20 seconds, and
the engine speed is 2,000 r p m or above for at least
10 seconds.
• W h e n the engine speed is 500 r p m or less, and the
vehicle is travelling at a speed of 6 m p h (10 km/h) or
more for about 3 seconds.
To determine the actual cause of the p r o b l e m , question
the customer about the conditions during w h i c h the
p r o b l e m occured, taking the above conditions into
consideration.
Diagnostic Trouble Code (DTC)
• If the CPU cannot be activated, or it fails, the EPS
indicator comes o n , but the DTC is not memorized.
• The m e m o r y can hold any n u m b e r of DTCs. However,
w h e n the same DTC is detected more than once, the
most recent DTC is written over the prior DTC,
therefore only one occurance is memorized.
• The lowest DTC is indicated first. The DTCs are
indicated in ascending order, not in the order that
they occurred.
• The DTCs are memorized in the EEPROM (non-
volatile m e m o r y ) therefore the memorized DTCs
cannot be erased by disconnecting the battery.
Perform the specified procedures to clear DTCs.
Self-diagnosis
Self-diagnosis can be classified into t w o categories:
• Initial diagnosis: Performed right after the engine
starts and until the EPS indicator goes off.
• Regular diagnosis: Performed right after the initial
diagnosis until the ignition switch is turned OFF.
The EPS control unit performs the f o l l o w i n g functions
w h e n a problem is detected by self-diagnosis:
1. Turns on the EPS indicator.
2. Memorizes the DTC.
3. Stops power assist and manual steering operation
resumes.
NOTE:
• W h e n DTC 23 (a p r o b l e m w i t h the circuit for
engine speed signal) is detected, the power
assist will return to normal w h e n the vehicle
speed is 6 m p h (10 km/h) or above.
• For DTCs 2 1 , 22 and 23 the EPS indicator will go
off automatically, and the system returns to
n o r m a l .
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