XJ-S Convertible (XJ27) L6-4.0L (1996)
Technical Service Bulletin # 18-53
Date: 971101
Adaptive Fueling System - Diagnostic Procedures
18-53
DTCs P1176, P1177, P1178, P1179 -
Adaptive Fuelling System -
Diagnostic Procedure
MODEL
1995-96 XJS (4.0L) Range
DATE
11/97
ISSUE:
The adaptive fuelling system operates within predefined adaption limits to maintain an optimum performance level. Both the Fuel Mass Flow Rate
(FMFR) and the Air Mass Flow Rate (AMFR) are monitored by the ECM to ensure they stay within the adaption limits. However, if a fuelling system
problem occurs and the adaption limits are exceeded, a Diagnostic Trouble Code (DTC) is then stored in the ECM. The engine Malfunction Indicator
Lamp (MIL) will illuminate to report the presence of the DTC. The MIL will stay illuminated until the DTC has been cleared using the PDU.
The flow charts which accompany this bulletin are provided to assist in diagnosing the above DTCs. Each DTC is represented by an individual flow
chart which is used in conjunction with PDU.
ACTION:
Note:
It is unlikely that replacing the mass air flow sensor (MAFS) will rectify the above DTC problems.
If one or more of the above DTCs are stored in the ECM, then the PDU should be used to identify and clear the DTC(s). After identifying the DTC(s)
use the appropriate diagnostic flow chart to diagnose the fault.
After repairing a fault described in the flow chart, complete the next flow chart instruction to "Reset and Check AMFR adaption" or "Reset and Check
FMFR adaption" to determine if the fault has or has not been successfully repaired. It is not necessary to check or reset adaptions if no faults are
identified. Resetting and checking the AMFR and FMFR adaptions is achieved by following the procedure (Check and Reset Adaption).
Note:
After completing Form S-93 send it to:
Product Investigation
Fax Number (201) 818-9763.