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Contents Wiring diagrams Section: Multiport Fuel Injection (mfi) - 3.7l & 4.2l v8 4v (aew, Abz) All sections

Checking function Audi A8 D2

Multiport Fuel Injection (mfi) - 3.7l & 4.2l v8 4v (aew, Abz) 8 illustrations ~528 words

Checking function

  1. Connect VAG1551 or VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at idle). See «VAG1551 OR VAG1552 SCAN TOOL (ST), CONNECTING AND SELECTING "ENGINE ELECTRONICS" ADDRESS WORD 01»(/audi/a8/d2-1994-1999/remont/ignition-system/#on-board-diagnostic-obd-37l-42l-v8-aew-abz) .

Indicated on display

VAG1552 Scan Tool Display - Checking Throttle Position Sensor (1 Of 3). Scheme 128

Scheme 128: VAG1552 Scan Tool Display - Checking Throttle Position Sensor (1 Of 3)
Scheme 128: VAG1552 Scan Tool Display - Checking Throttle Position Sensor (1 Of 3)
  1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08, and press -Q- button to confirm input.

Indicated on display

VAG1552 Scan Tool Display - Checking Throttle Position Sensor (2 Of 3). Scheme 129

Scheme 129: VAG1552 Scan Tool Display - Checking Throttle Position Sensor (2 Of 3)
Scheme 129: VAG1552 Scan Tool Display - Checking Throttle Position Sensor (2 Of 3)
  1. Press buttons -0-, -0- and -4- to input display group number 4 (004), and press -Q- button to confirm input.

Indicated on display

VAG1552 Scan Tool Display - Checking Throttle Position Sensor (3 Of 3). Scheme 130

Scheme 130: VAG1552 Scan Tool Display - Checking Throttle Position Sensor (3 Of 3)
Scheme 130: VAG1552 Scan Tool Display - Checking Throttle Position Sensor (3 Of 3)

Scheme 131

Scheme 131
Scheme 131
  1. Check specified values for basic functions with ignition switched on (display field 1). see scheme 128 see scheme 128: Display Group 4: Basic Functions, Ignition On

If throttle angle is not OK

  1. Check accelerator pedal cable adjustment. See «ACCELERATOR PEDAL CABLE, ADJUSTING»(/audi/a8/d2-1994-1999/remont/fuel-system/#fuel-supply-37l-42l-v8-4v-aew-abz__accelerator-pedal-cable-adjusting) .
  2. Press -->button to advance program sequence.
  3. Press buttons -0- and -6- to select "End Output" function 06, and press -Q- button to confirm input.

If accelerator pedal cable adjustment is OK

  1. Check Closed Throttle Position (CTP) switch and adjust as necessary. See «CLOSED THROTTLE POSITION (CTP) SWITCH, CHECKING»(/audi/a8/d2-1994-1999/remont/fuel-system/#multiport-fuel-injection-mfi-37l-42l-v8-4v-aew-abz__closed-throttle-position-ctp-switch-checking) . NOTE: When the CTP switch is adjusted, the TP sensor is also adjusted at the same time.

If CTP switch adjustment is OK

  1. Check voltage supply for TP sensor.

Scheme 132

Scheme 132: Checking voltage supply
Scheme 132: Checking voltage supply
  1. Disconnect harness connector from TP sensor.
  2. Switch ignition on.
  3. Connect multimeter US 1119 (Fluke 83 or equivalent) and check voltage between connector terminals 1 and 2, and between terminals 2 and 3. see scheme 129: Identifying TP Sensor Harness Connector Terminals Specified value: 4.5-5.5 volts

If both measurements are outside the specified range

  1. Check resistance of TP sensor. See «CHECKING RESISTANCE»(/audi/a8/d2-1994-1999/remont/fuel-system/#multiport-fuel-injection-mfi-37l-42l-v8-4v-aew-abz) .

If just one measurement is outside the specified range, check wiring to ECM as follows

Scheme 133

Scheme 133
Scheme 133
  1. Connect VAG1598/19 test box to ECM harness connector. See «VAG1598/19 TEST BOX, CONNECTING»(/audi/a8/d2-1994-1999/remont/fuel-system/#multiport-fuel-injection-mfi-37l-42l-v8-4v-aew-abz__vag159819-test-box-connecting). (Scheme 137): Identifying ECM Connectors
  2. Disconnect harness connector from TP sensor. NOTE: When repairing TP sensor connector terminals, use only gold-plated terminals.
  3. Check wiring for open or short circuits as follows: (Scheme 138): Identifying TP Sensor Harness Connector Terminals TP SENSOR CIRCUIT TEST: OPENS/SHORTS TP sensor connector terminal VAG1598/19 test box socket (ECM terminal) 1 A3 2 A19 3 A24
  4. If wiring is OK
  5. Replace ECM. See «ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REPLACING»(/audi/a8/d2-1994-1999/remont/fuel-system/#multiport-fuel-injection-mfi-37l-42l-v8-4v-aew-abz__engine-control-module-ecm-without-metal). Generate new readiness code. See «READINESS CODE, GENERATING»(/audi/a8/d2-1994-1999/remont/ignition-system/#on-board-diagnostic-obd-37l-42l-v8-aew-abz).
  1. Disconnect harness connector from TP sensor.
  2. Connect multimeter US 1119 (Fluke 83 or equivalent) and check resistance between connector terminals 1 and 2. Specified value: 1.5-2.6 kohm (Scheme 139): Identifying TP Sensor Terminals
  3. Check resistance between terminals 2 and 3. Specified value: 0...3 kohm
  4. Slowly open throttle valve to Wide Open Throttle (WOT) position. Specified value: 2...6 kohm

If one measured value is outside specified range

  1. Replace TP sensor.
  2. Check readiness code. See «READINESS CODE, CHECKING»(/audi/a8/d2-1994-1999/remont/ignition-system/#on-board-diagnostic-obd-37l-42l-v8-aew-abz) . If DTC memory has been erased, generate new readiness code. See «READINESS CODE, GENERATING»(/audi/a8/d2-1994-1999/remont/ignition-system/#on-board-diagnostic-obd-37l-42l-v8-aew-abz) .