PCR 2.1 FLAMES HC

shariz124 said:

Has anyone managed to do hardcut flames on a pcr2.1 for 1.6tdi cr? i have done many on EDC17x howeve...

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• The rev limiter intervention on PCR 2.1 works more through fuel quantity limitation rather than a hard injection cut, so simply raising the limiter and expecting the same bang/flame behavior won't work.
• The post-injection maps (if present) are structured differently — on some PCR 2.1 calibrations they are minimal or not active in the same operating regions as EDC17.
• The overrun fuel cut strategy on PCR 2.1 tends to cut cleaner and faster, so you need to specifically delay or disable the fuel cut on deceleration and manipulate the quantity that remains during overrun.

• Look at the overrun fuel cut-off maps/thresholds — you want to keep injecting small quantities during decel.
• Adjust the rev limiter type — find the injection cut vs. fuel quantity reduction strategy and force it toward a harder cut with residual fuel.
• Work with post-injection timing and quantity — late post-injections with retarded timing are what create the unburnt fuel in the exhaust.
• Check if there's a DPF regeneration post-injection strategy you can repurpose — on some PCR 2.1 cals this is the easiest path since the maps already exist for late injection.

Gemini said:

That's a common issue when moving from EDC17 to PCR 2.1 — the strategy is fundamentally different even though both are Bosch diesel ECUs.

On EDC17, the typical hardcut/burble approach involves manipulating the torque limiters and injection cut behavior at the rev limiter, often combined with post-injection adjustments. On PCR 2.1 (especially the 1.6 TDI CR variants), the torque management and injection control structure is organized differently:

• The rev limiter intervention on PCR 2.1 works more through fuel quantity limitation rather than a hard injection cut, so simply raising the limiter and expecting the same bang/flame behavior won't work.
• The post-injection maps (if present) are structured differently — on some PCR 2.1 calibrations they are minimal or not active in the same operating regions as EDC17.
• The overrun fuel cut strategy on PCR 2.1 tends to cut cleaner and faster, so you need to specifically delay or disable the fuel cut on deceleration and manipulate the quantity that remains during overrun.

General approach for PCR 2.1 flames/hardcut:

• Look at the overrun fuel cut-off maps/thresholds — you want to keep injecting small quantities during decel.
• Adjust the rev limiter type — find the injection cut vs. fuel quantity reduction strategy and force it toward a harder cut with residual fuel.
• Work with post-injection timing and quantity — late post-injections with retarded timing are what create the unburnt fuel in the exhaust.
• Check if there's a DPF regeneration post-injection strategy you can repurpose — on some PCR 2.1 cals this is the easiest path since the maps already exist for late injection.

Can you share which specific software version (SW number) you're working with? And is the DPF already removed in the calibration? That matters because if the DPF is still present, flames obviously won't exit the tailpipe regardless of the injection strategy.

Also, what tool are you using to read/write — and are you working in the full flash or just the calibration area?

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shariz124 said:

there is no overrun fuel maps, ive capped tq limiters, torque to fuel is higher and start of injecti...

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• Rev limiter type — Is there a map/switch that defines whether the limiter works by quantity reduction vs. injection suppression? On some PCR 2.1 cals there are two limiter strategies. You need the hard cut (injection on/off) not the soft quantity ramp-down.
• Injection quantity at rev limiter — Even if you've raised torque limiters, is the actual IQ (injection quantity in mm³) still being pulled to zero at the limiter? Check if there's a separate IQ ceiling map that's independent of the torque path.
• Post-injection maps — Even if there's no dedicated "overrun fuel" map, check for post-injection quantity and timing maps (often used for DPF regen). These can be repurposed to inject late fuel at the right RPM/load points. Is DPF removed from the cal?
• Cylinder-individual injection cut — Some PCR 2.1 cals cut individual cylinders sequentially at the limiter rather than all at once. This gives a smooth drop rather than a hard bang. Look for cylinder cut order or sequential limiter maps.

shariz124 said:

3736

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• Engine torque limiters (11/12) — Is there a limiter that caps torque to 0 Nm at/above 4200 RPM? If so, the torque request going into this conversion map is 0 Nm, and 0 Nm × anything = 0 fuel.
• Engine torque request (10/16) — Check the overrun/deceleration torque request maps. During throttle lift (foot off pedal), the ECU requests 0 or negative torque. You need to force a minimum positive torque request during overrun at high RPM.
• Injection system (35/35) — This is where the actual injection enable/disable logic likely lives. There may be an injection suppression or fuel cut flag/map that kills injection during overrun regardless of what the torque-to-fuel map says. This is probably your missing piece — look for maps related to injection enable conditions, overrun fuel cut RPM thresholds, or minimum injection quantity.
• Smoke limitation (12/12) — Could also be capping IQ back to 0 at that RPM range.

Gemini said:

Thanks for the screenshot — that's very helpful. I can see you're working in biunlook with the full mappack structure visible.

Looking at your 1D832C - Torque to fuel quantity map, I can see the key issue clearly:

At 4200 RPM you have 72.00 mm³ across all torque columns — that's your rev limiter point where you're forcing max fuel. Then at 4201 RPM it drops to 0.00 across the board — that's the hard cut. This is essentially the right idea for a hardcut flame strategy.

However — the problem is likely that the ECU is not actually injecting that 72mm³ at 4200 because other maps upstream are overriding it. The torque-to-fuel map only converts what the torque path requests. If the torque request itself is being killed before reaching this map, the 72mm³ never gets commanded.

Check these specific areas in your mappack:

• Engine torque limiters (11/12) — Is there a limiter that caps torque to 0 Nm at/above 4200 RPM? If so, the torque request going into this conversion map is 0 Nm, and 0 Nm × anything = 0 fuel.
• Engine torque request (10/16) — Check the overrun/deceleration torque request maps. During throttle lift (foot off pedal), the ECU requests 0 or negative torque. You need to force a minimum positive torque request during overrun at high RPM.
• Injection system (35/35) — This is where the actual injection enable/disable logic likely lives. There may be an injection suppression or fuel cut flag/map that kills injection during overrun regardless of what the torque-to-fuel map says. This is probably your missing piece — look for maps related to injection enable conditions, overrun fuel cut RPM thresholds, or minimum injection quantity.
• Smoke limitation (12/12) — Could also be capping IQ back to 0 at that RPM range.

The strategy difference vs EDC17 is exactly this: on PCR 2.1 the injection suppression during overrun is typically handled inside the injection system submaps, not as a standalone "overrun fuel cut" map. That's why you couldn't find it as a separate category.

Can you expand the Injection system (35/35) folder and share a screenshot of the map list? That's almost certainly where the fuel cut logic is hiding. Also check if there's anything in there named like "injection enable", "cylinder cut", "fuel cut threshold" or similar.

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shariz124 said:

3737

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• 1CDC78 / 1CDFD8 — Injection duration (these are the final pulse width maps)
• 1D7E2C / 1D80AC / 1D832C / 1D85AC — Torque to fuel quantity (you've already modified 1D832C)

• Injection quantity limitation / minimum injection quantity
• Injection enable/disable conditions
• Cylinder cut-off or sequential injection suppression
• Overrun injection quantity (might be labeled as "fuel quantity" at 0% pedal or idle/decel conditions)
• Post-injection quantity and timing (this is critical for flames — late post-injection = unburnt fuel in exhaust)

shariz124 said:

the rest are all torque to fuel quantity maps, and in soi its just start of injection, nohting else

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• Overrun fuel cut RPM threshold — typically a small 1D curve, RPM vs enable/disable. This is what kills injection when you lift the throttle.
• Minimum injection quantity — often a 2D map (RPM × coolant temp or RPM × pedal position). During overrun this goes to 0.
• Post-injection quantity + post-injection SOI — separate from main injection maps. These are what you'd use to push unburnt fuel into the exhaust.
• Rev limiter type/strategy — defines hard cut vs soft cut behavior.

shariz124 said:

SM2N00
SM2G0N0000000
CASM2N00SM2N000
ECM15TDI02103L906023RM
CASM2N00.DAT
6502026649
03L906023RM
826

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• DFPM enable RPM threshold — typically around 1300-1500 RPM. Below this RPM, fuel is restored. You need to raise this to above your limiter RPM (e.g. 9999) so the ECU never activates fuel cut during overrun.
• DFPM minimum throttle position — defines at what pedal % the ECU considers it "overrun." Usually 0-3%.

• Post-injection quantity map (RPM × load)
• Post-injection SOI offset (typically 40-80° ATDC)
• Post-injection enable conditions

• Overrun fuel cut disable
• Post-injection quantity/timing
• Limiter hard cut strategy

Gemini said:

Thanks for the full ident. So this is:

Bosch PCR 2.1 — 03L906023RM — 1.6 TDI CR (CAYC)

This is a common SW. The problem is confirmed — biunlook's definition for this SW is missing a large chunk of the functional maps.

For this specific ECU, the key areas you need to find manually are:

1. Overrun fuel cut (DFPM — Deceleration Fuel shutoff)

On PCR 2.1 CAYC, the overrun fuel cut is controlled by:

• DFPM enable RPM threshold — typically around 1300-1500 RPM. Below this RPM, fuel is restored. You need to raise this to above your limiter RPM (e.g. 9999) so the ECU never activates fuel cut during overrun.
• DFPM minimum throttle position — defines at what pedal % the ECU considers it "overrun." Usually 0-3%.

2. Post-injection (NE — Nacheinspritzung)

For flames on diesel you need late post-injection. On this SW there should be:

• Post-injection quantity map (RPM × load)
• Post-injection SOI offset (typically 40-80° ATDC)
• Post-injection enable conditions

These are what push unburnt fuel into the exhaust manifold.

What to do now:

Can you share the .ori bin file? With SW 03L906023RM I can look at the raw binary and give you the exact addresses for:

• Overrun fuel cut disable
• Post-injection quantity/timing
• Limiter hard cut strategy

Without those addresses, modifying only the torque-to-fuel and main SOI maps will never produce flames — the ECU is simply cutting injection on throttle lift before any of your modified maps get used.

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• The file is a partial read — only the boot/header area was read and the rest is empty/padded
• The read failed and the tool filled the file with 0xFF
• The file got corrupted during export/upload

• Calibration data roughly in the 0x1C0000–0x1FF000 range (this is where your maps at 1CDC78, 1D7E2C etc. sit)
• Code/program area from roughly 0x10000–0x1BFFFF
• Entropy well above 5-6 bits/byte for the data sections

1. What tool did you use to read this? (KTag, Autotuner, CMD, PCMFlash, etc.)
2. Was it a full read or partial/OBD read?
3. Open the file in a hex editor (HxD, WinOLS, etc.) and scroll to offset 0x1CDC78 — is there actual data there or still 0xFF?
4. What's the actual file size in bytes? Should be exactly 2,097,152 bytes (2MB) for a full read

Gemini said:

The file you uploaded is problematic — the entire hex preview (first 0x2000 bytes = 8KB) is nothing but 0xFF. That's a blank/erased flash header area, which is normal for the boot sector, but the fact that the entropy is reported as 0.00 bits/byte across the entire 2MB file is not normal.

This suggests one of the following:

• The file is a partial read — only the boot/header area was read and the rest is empty/padded
• The read failed and the tool filled the file with 0xFF
• The file got corrupted during export/upload

A valid 2MB PCR 2.1 ori for 03L906023RM should have:

• Calibration data roughly in the 0x1C0000–0x1FF000 range (this is where your maps at 1CDC78, 1D7E2C etc. sit)
• Code/program area from roughly 0x10000–0x1BFFFF
• Entropy well above 5-6 bits/byte for the data sections

Can you check the following:

1. What tool did you use to read this? (KTag, Autotuner, CMD, PCMFlash, etc.)
2. Was it a full read or partial/OBD read?
3. Open the file in a hex editor (HxD, WinOLS, etc.) and scroll to offset 0x1CDC78 — is there actual data there or still 0xFF?
4. What's the actual file size in bytes? Should be exactly 2,097,152 bytes (2MB) for a full read

If the file is genuinely all 0xFF, it's a dead read and we can't work with it. Re-read the ECU and upload again. If you have the file open in biunlook and can see map data, then the upload may have failed — try zipping it before uploading.

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shariz124 said:

read by flex magic, its a full obd read and yes 2mb

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• 0x1C0000 — start of calibration area, should be non-FF data
• 0x1CDC78 — this is where biunlook found your first injection maps
• 0x1D7E00 – 0x1D8000 — should contain more map data
• 0x1E0000 – 0x1E2000 — typically where overrun/fuel cut parameters sit on this SW

• DFPM or Schub or Overrun — fuel cut during deceleration
• NE or Nacheinspritzung or Post injection
• MBG or Mengen Begrenzung — quantity limitation / limiter
• ASG or Abregelung — rev limiter strategy