DaimlerChrysler Jeep Grand Cherokee 2002, Service Manual

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Symptom List:
P1235-EXTERNAL FUEL QUANTITY BIT ERROR
P1235-EXTERNAL FUEL QUANTITY DEMAND ERROR
P1235-EXTERNAL FUEL QUANTITY PARITY ERROR
P1235-EXTERNAL FUEL QUANTITY TORQUE ERROR
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P1235-EXTERNAL FUEL QUAN-
TITY BIT ERROR.
POSSIBLE CAUSES
CHECKING FOR TRANSMISSION CONTROL MODULE DTC’S
TRANSMISSION CONTROL MODULE
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIII
t
, read the TCM DTCs.
Are there any TCM DTC’s?
All
Yes
→
Refer to symptom list for problems related to TCM DTC’s.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Go To 2
2 NOTE: This DTC indicates a communication problem between the TCM and
the ECM.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Perform several engine run cycles, turning the ignition off for at least 20 seconds
between each engine run cycle.
With the DRBIII
t
, read the ECM DTCs.
Did this DTC set again?
All
Yes
→
Go To 3
No
→
Go To 4
3 Turn the ignition off.
Replace and program the Transmission Control Module in accordance with the
Service Information.
Turn the ignition on.
With the DRB, erase all ECM and TCM DTC’s.
Perform several engine run cycles, turning the engine off for at least 20 seconds
between each cycle.
With the DRBIII
t
, read the ECM DTCs.
Does the DRBIII
t
display this DTC
All
Yes
→
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Test Complete.
172
DRIVEABILITY - DIESEL
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