Fuel Pump (FP) Relay -J17- and Activation, Checking
Fuel Pump (FP) Relay -J17- And Activation, Checking
Special tools and equipment
- VAG1526A or Fluke 83 Multimeter
- VAG1594A Connector test kit
- VAG1598/31 Test box
- VAS5051 Vehicle diagnosis, testing and information system with VAS5051/1 Adapter
Voltage is supplied to the Fuel Pump (FP) and several components of the injection system via the Fuel Pump (FP) relay -J17-.
The engine must be turning for the Fuel Pump (FP) relay -J17- to close. This means that the relay does not receive a Ground (via ECM) until the ECM recognizes RPM signals.
Requirement
- Battery voltage at least 12.7 V
Function test of Fuel Pump (FP) relay
- Remove driver's side storage compartment:
- Connect VAS5051 tester, Vehicle Diagnostic, Testing and Information System VAS 5051, Connecting and Selecting Functions and select vehicle system "01 - Engine electronics". Ignition must be switched on for this.
- Initiate output Diagnostic Test Mode (DTM). Testing and Inspection
- Fuel Pump (FP) relay (at position 4 of central electronics in driver's footwell, left) must trigger and Fuel Pump (FP) must run.
- End function "03 - output Diagnostic Test Mode (DTM)" by pressing <- button.
A - If relay does not trigger:
- Check voltage supply of Fuel Pump (FP) relay. Testing and Inspection
- Checking activation of Fuel Pump (FP) relay. Testing and Inspection
B - If relay triggers, but Fuel Pump (FP) does not run:
- Check voltage supply for Fuel Pump (FP) and components (via Fuel Pump -FP- relay). Checking voltage supply of Fuel Pump (FP) relay
- Remove Fuel Pump (FP) relay.
- Connect multimeter to terminal 17 of relay socket and Ground (GND) for voltage measurement.
- Specified value: approx. battery voltage
If specified value is not obtained:
- Replace central electronics.
Checking activation of Fuel Pump (FP) relay
- Switch ignition off.
- Connect VAG1598/31 test box at wiring harness to Engine Control Module (ECM) but do not connect ECM. Scan Tool Testing and Procedures
- Bridge terminals 1 and 65 at test box using wires from VAG1594A connector test kit
- Switch ignition on.
- Fuel Pump (FP) relay (at position 4 of central electronics in driver's footwell, left) must trigger.
If relay triggers now, but did not during output DTM:
- Replace Engine Control Module (ECM).
If relay does not trigger:
- Switch ignition off.
- Remove wiring bridge.
- Remove Fuel Pump (FP) relay.
- Connect multimeter for voltage measurement as follows:
Central electronics in driver's Measure to
side footwell, left, position
4 Terminal
19 Engine Ground (GND)
- Switch ignition on.
- Specified value: approx. battery voltage
If specified value is not obtained:
- Check wiring connections
If specified value is obtained:
- Check following wiring connection for open circuit and short circuit to Ground (GND) and B+:
Central electronics in driver's GVAG1598/31 test box
side footwell, left, position Socket
4 Terminal
3 65
- Repair open circuit in wiring or short circuit if necessary.
If no malfunctions are detected:
- Replace Fuel Pump (FP) relay -J17-.
- Re-connect Engine Control Module (ECM).
Check voltage supply for Fuel Pump (FP) and components
- Disconnect fuses S228, S232, S234 and S243 (positions 28, 32, 34 and 43) from fuse holder.
- Initiate output Diagnostic Test Mode (DTM) Output Diagnostic Test Mode (Function 03) and activate Evaporative Emission (EVAP) canister purge regulator valve -N80-.
- Connect multimeter for voltage measurement to Ground (GND) and to one terminal of following fuses in fuse holder:
Circlip Specified value at one of the terminals
S228 approx. battery voltage
S232 approx. battery voltage
S234 approx. battery voltage
S243 approx. battery voltage
If specified values are not obtained:
- Repeat test at another terminal of fuse socket.
If specified values are not obtained again:
- Check wiring connections.
If no malfunctions are detected:
- Replace Fuel Pump (FP) relay -J17-.
- Re-insert fuses.