Checking holding pressure, engine codes AXD, AXE, BLJ, BNZ, BPC — VW
Checking holding pressure, engine codes AXD, AXE, BLJ, BNZ, BPC on VW: factory workshop procedure for engines AXB, AXC, AXD, AXE.
Workshop procedure for VW — the factory write-up, straight from real workshop data.
📐 38 workshop diagrams for AXB
Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.
📋 Procedure
ℹ️ Torque figures below come verbatim from workshop data — always cross-check against your vehicle's factory manual before final tightening.
Checking holding pressure, engine codes AXD, AXE, BLJ, BNZ, BPC
Special tools and workshop equipment required
Torque wrench
V.A.G 1331
Tandem pump tester
VAS 5187
Hose clamps up to 25 mm
3094
Vehicle diagnostic tester
Test prerequisites
Coolant temperature must be at least 85°C.
Unit injectors OK.
Fuel filter and fuel lines must not be blocked or damaged.
Procedure
Unbolt coolant expansion tank, and secure it using cable tie, for example.
Thoroughly clean plug and surrounding areas before disconnecting.
Unscrew plug
arrow
.
Note
Under no circumstances may dirt enter the hole of the tandem pump.
Ensure that no diesel fuel comes into contact with the coolant hoses. If necessary, clean immediately.
Observe disposal regulations.
Do not forget the seals for the
tandem pump tester
VAS 5187
.
Connect
tandem pump tester
VAS 5187
as shown.
Connect
Vehicle diagnostic tester
and choose operating mode
“Vehicle self-diagnosis”
.
Access engine electronics control unit by entering
“01”
.
Press diagnostic function
“08-Read measured value block”
.
Enter display group
“1”
using numeric key pad and confirm entry with
Q
key.
Start engine and run at idling speed.
Read off idling speed in display field 1.
Increase speed to 1500 rpm.
Check displayed pressure on pressure gauge.
Specification: at least 7.5 bar
Note
If necessary, seek assistance from a second person to clamp off fuel return hoses.
Clamp off fuel return hose (blue marking) of tandem pump with
hose clamps, up to 25 mm
3094
.
Clamp off fuel supply hose (white marking) to tandem pump with
hose clamps up to 25 mm
3094
. Stop engine.
Press
←
on
Vehicle diagnostic tester
.
Press
“06 - End output”
function.
Switch off ignition and disconnect
Vehicle diagnostic tester
.
Read off displayed pressure on pressure gauge after approx. 30 minutes.
Specification: approx. 3.0 bar
Read off pressure again after approx. 60 minutes:
Specification: approx. 2.5 bar
If the specified value is not reached, there is a leak.
Perform further checks as follows:
Connections of fuel supply line
Connections of fuel return line
Fuel hoses
Shaft seals on tandem pump
Chapter
Seals on unit injector
Rep. gr.
23
Injectors/high-pressure accumulator (fuel rail)
Within cylinder head
Note
Ensure that no diesel fuel comes into contact with the coolant hoses. If necessary, clean immediately.
Observe disposal regulations.
Always renew plug with seal.
Remove
tandem pump tester
VAS 5187
.
Screw in new plug
arrow
finger-tight, then tighten it to specified torque.
Specified torques
Component
Specified torque
Plug
25 Nm
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
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Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.