1999 AUDI A4 trip computer

24-95

Fuel consumption signal, checking


Notes:

The consumption signal is internally calculated
by the ECM using "injection time."
The consumption signal is routed to both the
trip computer and the Transmission Control
Module (TCM).
The consumption signal is monitored by the
TCM

Repair Manual, 5 Spd. Automatic
Transmission 01V, Repair Group 01; On Board Diagnostic

Carry out the following check only if DTC
memory contains a stored DTC for the TCM
related to the consumption signal, or a missing or
false consumption signal, determined during the
trip computer check.

- Remove instrument cluster or TCM.

Repair Manual, Electrical Equipment, Repair
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24-96

- Switch Fluke 83 multimeter to voltage
measurement range and connect between
signal wire (trip computer 20-pin connector) and
Ground (GND), using wiring diagram.

- Start engine and let idle.

Specified value: approx. 0.3 to 0.6 volts,
corresponding to engine speed (RPM)

- Vary engine speed continuously from 1000 to
4000 RPM.

Specified value: approx. 0.3 to 0.6 volts,
corresponding to engine speed (RPM)
If the specified value is not obtained, even
though the trip computer shows no consumption
value or there is a stored malfunction in the
TCM:

- Stop engine (switch ignition off).

- Replace trip computer and/or TCM as
required.
If the specified value is not obtained:

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If wiring OK and the specified value is not obtained: - Check wiring between ECM terminal C12 and black 20-pin trip
computer connector, using wiring diagram.
- Replace ECM page 01
-265
.
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