A malfunction is
detected by using a checksum technique for verifying data. The digital
data is composed of zeros and ones. A checksum is the total of all ones in
a string of data. By comparing the checksum value with a stored value, a
malfunction can be detected.
If CPU software version
does not accord with main CPU, PCM sets P0602.
Item
|
Detecting
Condition
|
Possible cause
|
DTC
Strategy
|
|
|
Enable
onditions
|
|
Threshold
value
|
| •
|
The version discordance among PCU S/W or
Calibration | |
Diagnosis
Time
|
|
MIL On
Condition
|
|
| 1. |
Check DTC Status
| (1) |
Connect scantool to Data Link
Connector(DLC). |
| (3) |
Select "DTC" button, and then Press "DTC
Status" to check DTC's information from the DTCs
menu. |
| (4) |
Read "DTC Status"
parameter.
|
| (5) |
Is parameter displayed "Present
fault"?
|
|
▶ Go
to "Terminal and connector inspection"
procedure.
|
|
|
▶
Fault is intermittent caused by poor contact in the
sensor's and/or PCM's connector or was repaired and PCM
memory was not cleared. Thoroughly check connectors for
looseness, poor connection, ending, corrosion,
contamination, deterioration, or damage. Repair or
replace as necessary and go to "Verification of Vehicle
Repair"
procedure.
|
| |
| Terminal And Connector
Inspection |
| 1. |
Many malfunctions in the electrical system are
caused by poor harness 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 go to "Verification of Vehicle Repair"
procedure
|
|
|
▶
Substitute with a known-good PCM and check for proper
operation. If the problem is corrected,replace PCM and then go
to "Verification of Vehicle Repair"
procedure.
|
|
There is a memory reset function on
scantool that can erase optional parts automatically detected
and memorized by PCM. After testing PCM on the vehicle, use
this function before reusing the
PCM | |
| Verification Of Vehicle
Repair |
After a repair, it is
essential to verify that the fault has been corrected.
| 1. |
Connect scantool and select "DTC"
button. |
| 2. |
Press "DTC Status" button and confirm that
"DTC Readiness Flag" indicates "Completed". If not, drive the
vehicle within conditions noted in the freeze frame data or enable
conditions |
| 3. |
Read "DTC Status"
parameter |
| 4. |
Is parameter displayed "History(Not Present)
fault"?
|
|
▶ System
performing to specification at this time. Clear the
DTC
|
|
|
▶ Go to the
applicable troubleshooting
procedure.
|
|
