The 4WD vehicle measures
the G-sensor signal to solve for 4WD vehicle unique problems. For example
all 4 wheels are locked early on a low-friction road or control response
is delayed when road friction coefficients vary. The HECU uses a filtered
signal, as a supplementary value, to determine the road friction
coefficient. This value is used for the accurate calculations of assumed
vehicle speed, or precise division of control starting
points.
The HECU monitors the
G-sensor voltage continuosly,and sets this code if the voltage is either
higher than the permissible normal value ( approx. 4.5 V ) or lower than
the value ( approx. 0.6V ) for more than 250ms.
Item
|
Detecting
Condition
|
Possible cause
|
DTC
Strategy
|
|
| •
|
Open or short of G-Sensor
circuit |
|
Enable
Conditions
|
| •
|
When the voltage of G sensor signal is
>4.5±0.1V or
< 0.6±0.1V for 250msec
continuously. | |
Fail
Safe
|
| •
|
ABS/ESC functions are inhibited, EBD
function is allowed and the ABS/ESC warning lamps are
activated. | |
| 1. |
Connect scantool to Data Link
Connector(DLC). |
| 2. |
Ignition "ON" & Engine
"OFF". |
| 3. |
Monitor the "G Sensor" parameter on the
Scantool.
Specification
: Approx. ±0.01G
|
|
| 4. |
Is parameter displayed within
specifications?
|
|
▶ Fault is
intermittent caused by poor connection in G sensor harness
and/or HECU's connector or was repaired and HECU memory was
not cleared.
Thoroughly check
connectors for looseness, poor connection, bending, corrosion,
contamination, deterioration, or damage.
Repair or replace as necessary and then go to
"Verification Of Vehicle Repair" procedure.
|
|
|
▶ Go to
"Terminal and Connector Inspection"
procedure.
|
|
| Terminal and Connector
Inspection |
| 1. |
Many malfunctions in the electrical system are
caused by poor harness(es) and terminal condition. Faults can also
be caused by interference from other electrical systems, and
mechanical or chemical damage. |
| 2. |
Thoroughly check connectors for looseness,
poor connection, bending, corrosion, contamination, deterioration,
or damage. |
| 3. |
Has a problem been found?
|
|
▶ Repair as
necessary and then go to "Verification Of Vehicle Repair"
procedure.
|
|
|
▶ Go to
"Power Circuit Inspection"
procedure.
|
|
Open or Short Check
| 1. |
Ignition "ON" & Engine
"OFF". |
| 2. |
Measure voltage between power terminal of the
G sensor harness connector and chassis ground.
Specification
: Approx. 5V
| |
| 3. |
Is the measured value within
specifications?
|
|
▶ Go to
"Ground Circuit Inspection" procedure.
|
|
|
▶ Repair
open or short in power circuit between the G sensor harness
connector and HECU harness connector and then, go to
"Verification Of Vehicle Repair" procedure.
▶ If there is no problem in Power circuit,
Substitute with a known-good HECU and check for
properoperation.
If problem is
corrected, replace HECU and then go to "Verification Of
Vehicle Repair"
procedure.
|
|
| Ground Circuit
Inspection |
Open or Short Check
| 1. |
Ignition "OFF" & Engine
"OFF". |
| 2. |
Disconnect the G sensor
connector. |
| 3. |
Measure resistance between ground terminal of
the G sensor harness connector and chassis ground.
Specification
: Approx. below 1Ω
| |
| 4. |
Is the measured value within
specifications?
|
|
▶ Go to
"Signal Circuit Inspection" procedure.
|
|
|
▶ Repair
open or short in ground circuit between the G sensor harness
connector and HECU harness connector and then, go to
"Verification Of Vehicle Repair"
procedure.
|
|
| Signal Circuit
Inspection |
Open or Short Check
| 1. |
Ignition "ON" & Engine
"OFF". |
| 2. |
Measure voltage between G sensor signal
terminal of the HECU harness connector and chassis
ground.
Specification
: Approx. 2.5V
| |
| 3. |
Is the measured value within
specifications?
|
|
▶
Substitute with a known-good HECU and check for proper
operation.
If problem is corrected,
replace HECU and then go to "Verification Of Vehicle Repair"
procedure.
|
|
|
▶ Repair
open or short in signal circuit between the G sensor harness
connector and HECU harness connector, and then go to
"Verification Of Vehicle Repair" procedure.
▶ If there is no problem in Signal circuit, Go to
"Component Inspection"
procedure.
|
|
Open or Short Check
| 1. |
Ignition "ON" & Engine
"OFF". |
| 2. |
Measure voltage between signal terminal of the
G sensor harness connector and chassis ground.
Specification
: Approx. 2.5V
| |
| 3. |
Is the measured value within
specifications?
|
|
▶ Fault is
intermittent caused by poor connection in G sensor harness
and/or HECU's connector.
Go to
"Verification Of Vehicle Repair" procedure.
|
|
|
▶
Substitute with a known-good G sensor and check for proper
operation
If problem is corrected,
replace G sensor and then go to "Verification Of Vehicle
Repair"
procedure.
|
|
| Verification of Vehicle
Repair |
After a repair, it is
essential to verify that the fault has been corrected.
| 1. |
Connect scantool and select "Diagnostic
Trouble Codes(DTCs)" mode. |
| 2. |
Using a scantool, Clear
DTC. |
| 3. |
Operate the vehicle within DTC Detecting
Condition in General Information. |
| 4. |
Using a scantool, Check DTC
present. |
| 5. |
Are any DTCs present ?
|
|
▶ Go to the
applicable troubleshooting procedure.
|
|
|
▶ System
performing to specification at this
time.
|
|
