Subject: Diagnostic Trouble Code (DTC) P1127, P1129, or P1557
Stored in DTC Memory
Model(s):S4, A6, allroad with 2.7L
(Eng. code APB, BEL)
2000 - 2003
Date: May 6, 2003
Supersedes T.B. Repair Group 01 number 0004 dated Aug. 18, 2000
DTC P1127 and/or P1129 and/or P1557stored
in DTC memory.
Can also be accompanied by poor throttle
response or engine shake at steady speeds.
May be caused by loss of pressure from the
turbocharger due to cracks or tears in the
intake air duct "Y" boot under the fastening
-Remove upper engine cover -C- only (see
Repair Manual Group 15 Cylinder head
covers removing and installing).
- Remove bolts -1- for pressure hoses.
-Allows hose to move when removing "Y"
hose from Throttle Valve Control Module
- Remove Charge Air Pressure Sensor (G31)
Make note of clamp orientation and position.
- Loosen clamps -1- to pressure hoses.
- Loosen clamp -3- at Throttle Valve Control
- Remove Intake air duct ("Y" hose) from
Throttle Valve Control Module -J338- and
If intake air duct is cracked or torn it must be
A tear may have been caused by sharp edges
on Throttle Valve Control Module -J338- connecting
flange cutting into the rubber duct (arrow)
which connects to pressure hoses.
Prior to installing new duct:
- Remove four Throttle Valve Control Module
- Remove Control Module.
- Using a round file, round over sharp outer
edges of the inner groove and outer edge of
control module -arrows- (around the entire
periphery of control module) to a maximum
radius of 0.5 mm (approx. 0.02 in.).
- Using 120 grit emery cloth, finish outer edges
of the inner groove and outer edge of control
module -arrows- (around the entire
periphery of control module).
- After rework is finished, clean shavings and
any accumulated dirt/oil film from outer and
inner surfaces of control module using air
pressure and solvent (brake cleaner works
- For heavier deposits of dirt / oil film, apply
Wynns XTend V.I.C. Combustion
Chamber Cleaner: Part No: 61510 (U.S.),
Part No: 61512 (CAN.) on a soft clean cloth
then, clean interior surfaces using this cloth
(one can of cleaner will do many vehicles,
therefore it is considered shop supply).
- Clean the interior surfaces of throttle valve
control module -J338- housing with a soft
- Reinstall Throttle Valve Control Module
-J338- using a new gasket (see table).
-Fastener torque = 10Nm. +or- 1Nm.
-Install new parts as follows.
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