Fuel consumption signal, testing
Special tools and equipment
- Multimeter Fluke 83 (or equivalent)
- VAG 1598 test box with VAG 1598/25 adapter
- VAG 1594 connector test kit
- Test box for relevant Engine Control Module (ECM)
Scan Tool (ST) and test equipment safety precautions
WARNING:
- Due to weight, size and need for manual operation of test instruments while vehicle is driven on public roads, instrument must be used only with a Driver operating the vehicle and an Instrument Operator operating the test equipment.
- Do not use Instrument with Driver only. Always use two persons to conduct test.
- Do not place Instrument on lap of Driver or front seat passenger because emergency stop may dislodge Instrument and cause airbag deployment with risk of injury to Instrument Operator.
WARNING:
Use of Instrument in Audi TT Coup:
- Place Instrument in rear seating area and secure by available safety belt.
- Instrument Operator must be seated in the other rear seating position, after sliding front passenger seat and moving the seat back as far forward as possible. Do not activate the seat back release lever.
- Instrument Operator must wear safety belt.
Use of Instrument in Audi TT Roadster:
- Use only Instrument VAG 1551/1552 or VAS 5052. DO NOT USE VAS 5051.
- Before test, deactivate passenger's airbag using key operated switch in glove compartment.
- Instrument Operator must be seated on passenger seat with safety belt worn.
- Place Instrument in foot well in front of passenger seat in a manner allowing the Operator to use the Instrument in a safe manner.
- After completion of test, re-activate front passenger airbag.
CAUTION:
To prevent damage to electronic and electrical components, note the following:
- Always switch off the ignition before connecting or disconnecting test instruments.
- During some of the tests the control module may identify and record DTCs. The Diagnostic Trouble Code (DTC) memory should therefore be checked and (if necessary) erased after completing the tests and any repair work that may be required.
- Start engine and perform road test. Observe consumption display in instrument cluster
What is indicated in consumption display?
1. Always 0.0 L/100 km
- Signal wire may have a short circuit to Ground
- Switch ignition off.
- Connect relevant test box to Engine Control Module (ECM).
Refer to
- 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AMU
- 28 IGNITION/GLOW PLUG SYSTEM for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): ATC
- 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AWP
- 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): BEA
- 24 - MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO GENERIC SCAN TOOL ENGINE CODE(S): AMU, BEA, ATC, AWP
- 24 MULTIPORT FUEL INJECTION (MFI) for 3.2 LITER V6 4V FUEL INJECTION & IGNITION, ENGINE CODE(S): BHE
- 24 - MULTIPORT FUEL INJECTION (MFI) for 3.2 LITER V6 4V GENERIC SCAN TOOL, ENGINE CODE: BHE
- Remove instrument cluster. Refer to Instrument cluster, removing and installing and disconnect blue 32-pin connector from instrument cluster.
- Connect VAG 1598 test box to blue 32-pin connector using VAG 1598/25 adapter.
- Connect (+) test lead to VAG 1598/25 socket 25 using multimeter.
- Connect (-) test lead to relevant test box of Engine Control Module (ECM) and the related consumption signal socket of the ECM.
- Perform resistance measurement.
Specification: display < 2 Ohm
- Connect (+) test lead to relevant test box of Engine Control Module (ECM) using multimeter.
- Connect (-) test lead to Ground.
- Perform resistance measurement.
Specification: display < 9 MOhm
- If specified value is not obtained, wiring connection is OK.
2. Always 51 L/100 km
- Signal wire may have an open circuit
- Switch ignition off.
- Connect test box to Engine Control Module (ECM).
Refer to
- 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AMU
- 28 IGNITION/GLOW PLUG SYSTEM for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): ATC
- 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AWP
- 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): BEA
- 24 - MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO GENERIC SCAN TOOL ENGINE CODE(S): AMU, BEA, ATC, AWP
- 24 MULTIPORT FUEL INJECTION (MFI) for 3.2 LITER V6 4V FUEL INJECTION & IGNITION, ENGINE CODE(S): BHE
- 24 - MULTIPORT FUEL INJECTION (MFI) for 3.2 LITER V6 4V GENERIC SCAN TOOL, ENGINE CODE: BHE
- Remove instrument cluster. Refer to Instrument cluster, removing and installing and disconnect blue 32-pin connector from instrument cluster.
- Connect VAG 1598 test box to blue 32-pin connector using VAG 1598/25 adapter.
- Connect (+) test lead to VAG 1598/25 socket 25 using multimeter.
- Connect (-) test lead to relevant test box of Engine Control Module (ECM) and the related consumption signal socket of the ECM.
- Perform resistance measurement.
Specification: display < 2 Ohm
- Connect (+) test lead to relevant test box of Engine Control Module (ECM) using multimeter.
- Connect (-) test lead to Ground.
- Perform resistance measurement.
Specification: display < 9 MOhm
- If specified value is not obtained, wiring connection is OK.
3. Consumption gauge indication is illogical or constantly varying consumption value
- Consumption gauge indication does not match actual fuel consumption.
- Perform adaptation of fuel consumption gauge.