DTC P1104 - LDE or LLU
Diagnostic Instructions
DTC Descriptor
DTC P1104 00: Throttle Actuator
Control (TAC) Motor Control Circuit Shorted
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Motor Control 1
|
P1516 00, P2101 00, P2176 00
|
P1516 00, P2101 00, P2176 00
|
P1516 00, P2101 00, P2176 00
|
P1516 00, P2101 00, P2176 00, P1104 00
|
Motor Control 2
|
P1516 00, P2101 00, P2176 00
|
P1516 00, P2101 00, P2176 00
|
P1516 00, P2101 00, P2176 00
|
P1516 00, P2101 00, P2176 00, P1104 00
|
Circuit/System Description
The engine control module (ECM) is the control centre for
the throttle body throttle actuator control (TAC) system. The
ECM determines the drivers intent and then calculates the
appropriate throttle response. The ECM achieves throttle
positioning by providing a pulse width modulated voltage to the
throttle body (TAC) motor. The throttle body (TAC) motor
system uses the following circuits:
• |
Throttle body (TAC) motor control 1 |
• |
Throttle body (TAC) motor control 2 |
Two processors are also used to monitor the throttle
body (TAC) motor system data. Both processors are located
within the ECM. Both processors monitor each others data to verify
that the indicated throttle position is correct.
Conditions for Running the DTC
P1104 00
• |
The ignition is ON or the engine is
operating. |
• |
The ignition voltage is greater than
7 V. |
• |
The system is not in battery safe mode. |
• |
DTC P0068 00 is not set. |
• |
DTCs P1516 00 and P2101 00 run
continuously once the above conditions are met for greater than
5 s. |
Conditions for Setting the DTC
P1104 00
The indicated throttle position does not match the predicted
throttle position for more than 0.5 s.
Action Taken When the DTC Sets
DTCs P1104 00 is a Type B DTC.
Conditions for Clearing the DTC
DTCs P1104 00 is a Type B DTC.
Diagnostic Aids
• |
A high resistance condition with the throttle
position sensor circuits may cause DTCs P1516 00,
P2101 00, P2119 00, or P2176 00 to set. |
• |
Inspect for a condition in which the throttle
valve may have been held open. For example, ice may have formed in
the throttle bore causing the throttle valve not to close. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, engine OFF, use a scan tool to observe
the throttle position sensor 1 indicated position. Throttle
position should increase as pedal is applied and decrease as pedal
is released. When no accelerator pedal activity is detected, the
throttle position will return to the spring loaded default
position.
Note: A low voltage condition
may set this DTC.
- Review the freeze frame/failure records and ensure
sufficient ignition voltage was present when the DTC was set.
⇒ |
If voltage was low, verify with the owner that the
battery was not discharged. If the battery has not been discharged,
refer to
Power Mode Mismatch . |
- Operate the vehicle within the conditions for running
the DTC. You may also operate the vehicle within the conditions
that you observed from the freeze frame/failure records data.
Circuit/System Testing
Warning: Turn OFF the ignition
before inserting fingers into the throttle bore. Unexpected
movement of the throttle blade could cause personal
injury.
- Inspect the Q38 Throttle Body for the following
conditions:
• |
A throttle blade that is not in the rest
position |
• |
A throttle valve that is binding open or
closed |
• |
A throttle valve that opens or closes without
spring pressure |
⇒ |
If a condition is found, replace the
Q38 Throttle Body. |
Note: Disconnecting the
throttle body harness connector causes additional DTCs to
set.
- Ignition OFF, disconnect the harness connector of the
Q38 Throttle Body.
- Verify that a test lamp does not illuminate between
Q38 Throttle Body motor control 1 circuit terminal A
or Q38 Throttle Body motor control 2 circuit
terminal B and ground.
⇒ |
If the test lamp illuminates, test the appropriate
Q38 Throttle Body motor control circuit for a short to
voltage. If the circuit tests normal, replace the K20 Engine
Control Module. |
- Disconnect the harness connector X2 from the
K20 Engine Control Module.
- Verify that a test lamp does not illuminate between
Q38 Throttle Body motor control 1 circuit terminal A
or Q38 Throttle Body motor control 2 circuit
terminal B and ground.
⇒ |
If the test lamp illuminates, test the appropriate
Q38 Throttle Body motor control circuit for a short to
voltage. |
- Connect the harness connector X2 on the
K20 Engine Control Module.
- Ignition ON, Verify that a test lamp illuminates
between Q38 Throttle Body motor control 1 circuit
terminal A or Q38 Throttle Body motor control 2
circuit terminal B and ground.
⇒ |
If the test lamp does not illuminate, test the
appropriate Q38 Throttle Body motor control circuit for an
open circuit or a short to ground. If the circuit tests normal,
replace the K20 Engine Control Module. |
- If all circuits test normal, replace the
Q38 Throttle Body.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
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