Engine Controls - Revised DTC P1125 Information
File In Section: 06 - Engine/Propulsion SystemBulletin No.: 03-06-04-031
Date: June, 2003
SERVICE MANUAL UPDATE
Subject:
Revised DTC P1125
Models:
2003 Cadillac Escalade, Escalade ESV, Escalade EXT
2003 Chevrolet Avalanche, Kodiak, Silverado, Suburban, Tahoe, TrailBlazer, TrailBlazer EXT, W Series Medium Duty Tilt Cab
2003 GMC Envoy, Envoy XL, Sierra, Sierra Denali, TopKick, W Series Medium Duty Tilt Cab, Yukon, Yukon Denali, Yukon Denali XL, Yukon XL
2003 HUMMER H2
with 4.8L, 5.3L, 6.0L or 8.1L Engine (VINs V, P, T, U, N, G - RPOs LR4, LM4, LM7, LQ4, LQ9, L18)
This bulletin is being issued to revise DTC P1125 in the Engine Controls sub-section of the Service Manual. Please replace the current information in the Service Manual with the following information.
The 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.
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. The APP sensor 1 signal voltage is low at rest and increases as the pedal is depressed. APP sensor 2 signal voltage is near the reference voltage at rest and decreases 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
^ Inspect 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 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Remember this if you review the information stored in Captured Info.
^ For an intermittent, refer to Intermittent Conditions.
Disclaimer