Recent Posts11
Mk5 General Area / Re: GTI V won't start, no lights on dashboard, issue with relay 460 (B1)?
« Last post by FOXOFF on March 13, 2026, 09:32:22 am »PLEASE PLEASE PLEASE HELP!!!
Hi Guys,
Audi A3 2.0 TFSI BWA 8P – Cranks but Won’t Start, No CEL
Symptoms:
Engine cranks but won’t start
No check engine light
Throttle body whines normally on ignition
Sunroof and boot lock not working
What I’ve Checked:
Relay 167 clicks when pin 85 is manually grounded
Pin 86 = +12 V ignition feed ✅
Pin 85 = +12 V (ECU is NOT grounding it) ❌
ECU has permanent +12 V and good ground ✅
Bridging relay pin 85 to ground powers F6–F12 fuses and fans run
F6–F12 fuses normally show low voltage
Observations:
With key ON, pin 85 of relay 167 stays at +12 V, so the relay doesn’t energize → ECU fuse rails not powered → no start, no CEL
Manually grounding pin 85 closes relay and powers downstream circuits, proving relay and fuses are good
F33 in the engine bay type 1 fuse box is for the fuel pump and unrelated to this ignition feed issue
Suspected Cause:
ECU is not detecting ignition ON, or its internal relay driver for pin 85 is not working
Likely culprit: Body Control Module (J519), which distributes ignition signals to multiple systems
Why BCM fits the symptoms:
Sunroof stops working ✅
Boot release stops working ✅
ECU relay 167 not triggered ✅
No CEL ✅
Random electrical loss ✅
BCM Location:
Under driver-side dash, above pedals
Checks Before Suspecting ECU:
Power supply to J519 (check both permanent +12 V and ignition-switched +12 V feeds)
Inspect connectors for corrosion, water ingress, or loose pins
Bottom line:
If the J519 isn’t sending the ground to relay 167, the ECU never gets switched 12 V → no start, no CEL. Fixing BCM power or connector issues often resolves this without touching the ECU.
Request:
Has anyone seen this exact crank/no start, no CEL, relay 167 issue on a BWA 8P? Any advice on checking the J519 or its ignition signals before considering ECU replacement?
Hi Guys,
Audi A3 2.0 TFSI BWA 8P – Cranks but Won’t Start, No CEL
Symptoms:
Engine cranks but won’t start
No check engine light
Throttle body whines normally on ignition
Sunroof and boot lock not working
What I’ve Checked:
Relay 167 clicks when pin 85 is manually grounded
Pin 86 = +12 V ignition feed ✅
Pin 85 = +12 V (ECU is NOT grounding it) ❌
ECU has permanent +12 V and good ground ✅
Bridging relay pin 85 to ground powers F6–F12 fuses and fans run
F6–F12 fuses normally show low voltage
Observations:
With key ON, pin 85 of relay 167 stays at +12 V, so the relay doesn’t energize → ECU fuse rails not powered → no start, no CEL
Manually grounding pin 85 closes relay and powers downstream circuits, proving relay and fuses are good
F33 in the engine bay type 1 fuse box is for the fuel pump and unrelated to this ignition feed issue
Suspected Cause:
ECU is not detecting ignition ON, or its internal relay driver for pin 85 is not working
Likely culprit: Body Control Module (J519), which distributes ignition signals to multiple systems
Why BCM fits the symptoms:
Sunroof stops working ✅
Boot release stops working ✅
ECU relay 167 not triggered ✅
No CEL ✅
Random electrical loss ✅
BCM Location:
Under driver-side dash, above pedals
Checks Before Suspecting ECU:
Power supply to J519 (check both permanent +12 V and ignition-switched +12 V feeds)
Inspect connectors for corrosion, water ingress, or loose pins
Bottom line:
If the J519 isn’t sending the ground to relay 167, the ECU never gets switched 12 V → no start, no CEL. Fixing BCM power or connector issues often resolves this without touching the ECU.
Request:
Has anyone seen this exact crank/no start, no CEL, relay 167 issue on a BWA 8P? Any advice on checking the J519 or its ignition signals before considering ECU replacement?
