Engine Controls - Revised DTC P1125
TSB SB03-01-S005Revised DTC P1125 (Service Manual Revision)
ISSUE DATE: OCTOBER 2003
Affected Vehicles
2003 Isuzu Ascender models equipped with 5.3L V8 engines.
Service Information
This bulletin is being issued to revise DTC P1125 in the Engine Controls section of the Service Manual. Please replace the current information in the Service Manual with the following information. The following information has been updated within SI. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.
NOTE:
Information released on paper and electronic format prior to bulletin release cannot be updated.
Service Manual Revision
DTC P1125
Circuit Description
The accelerator pedal position (APP) sensor 1 and APP sensor 2 are potentiometer type sensors, each with the following circuits:
^ A 5-volt reference circuit
^ A low reference circuit
^ A signal circuit
The control module provides the APP sensors a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the control module signal voltages proportional to pedal movement. APP sensor 1 and APP sensor 2 signal voltages are low at rest and increase as the pedal is depressed. when the control module detects that, the APP sensor 1 and the APP sensor 2 signal circuits are out of correlation with each other, DTC P1125 sets.
Conditions for Running the DTC
^ DTC P2108 is not set.
^ The ignition is in the crank or run position.
^ The ignition voltage is more than 5.23 volts.
^ The communication between the TAC module and the powertrain control module (PCM) must be valid.
Conditions for Setting the DTC
The PCM detects that the difference between APP sensor 1 and APP sensor 2 is more than the predicted value.
Diagnostic Aids
^ The the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
^ The APP sensor 1 and the throttle position (TP) sensor 1, 5-volt reference circuits are internally connected within the TAC module.
^ The APP sensor 2 and the TP sensor 2, 5-volt reference circuits are internally connected within the TAC module.
^ When the TAC module detects a condition within the TAC system, more than one (1) TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one (1) individual condition may correct more than one (1) DTC. Remember this if you review the information stored in Captured Info.
^ For an intermittent, refer to Intermittent Conditions.
DTC P1125
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