INTERPRETING B6 ENGINE DATA LOG

INTERPRETING PASSAT B6 TDI ENGINE MEASURING BLOCK DATA.

The figures given here are not gospel. They are a mixture of VW specifications and personal experience.

The B6 Tdi engines are very “self aware”, especially the 2.0 tdi, so most common running faults will set a fault code.

GREEN text gives typical or expected values.

001. Injection Quantity (Not useful for diagnosis)

1. Engine Speed(G28), Idle 800 rpm +/- very little. (819 rpm for 1.9)

To check idle speed you need to log block 001 for several minutes. The idle should be stable and vary very little.

2. Injection Quantity, Idle 3.0...7.0 mg/Stroke.

3. Injection Duration,(specified), Idle 2.0...5.0 °CR

4. Coolant Temperature (G62), Hot 80.0...110.0 °C will read 90°C on dash guage

INJECTION IS MORE PRECISELY CONTROLLED IN THE 2.0 PD than in the 1.9 PD.

002. Idle Speed This block tells you very little for fault finding.

1. Engine Speed,(G28), Idle 800 rpm

2. Accelerator Pedal Position Sensor 1 (G79), Idle = 0.0 %. Maximum = 100.0 %

3. Operation Status

00000001 = Climate Control ON

00001000 = Idle Switch closed

00010000 = Kick-Down (only Automatic Transmission)

01000000 = Idle Speed raised

4. Coolant Temperature (G62), Hot 80.0…110.0 °C

003. Exhaust Gas Recirculation (EGR)

You can only test the MAF & EGR function by doing a log from idle to 3500 rpm.

1. Engine Speed,(G28),Idle 800 rpm.

2. Exhaust Gas Recirculation. (specified), Idle 300…400 mg/Stroke.

3. Exhaust Gas Recirculation. (actual), Idle 300…400 mg/Stroke.

A constant value of approx 470 mg/stroke means a failed MAF.

4. Exhaust Gas Recirculation. Duty Cycle. Idle 0.0%. Full Load 0.0 %. rest of revs 15…70 %

A constant duty cycle value means the EGR valve is stuck or the control is faulty.

Note: The Mass Air Flow (MAF) is measured by the Air Mass Meter (AMM sometimes known as MAF).

This is a measurement of the Mass of air being sucked into the engine per Stroke.

If the MAF figure is high the EGR must be low or zero (Valve shut)

(For some reason the 2.0 pd engine specifies a MAF/EGR of 1388.8 mg/stroke when at idle with the EGR shut.).

The EGR specified follows a set pattern. At idle the figure is about 350 mg/str. When the accelerator is pressed this figure rises rapidly to 800 mg/str and stays there through the rev range.

Typically the EGR actual figure follows the specified figure. It is normal for the figure to over shoot the 800 mg/str set point and have to come back down. As long as the actual figure roughly follows the specified figure, it is ok.

A constant figure of roughly 470 mg/stroke means the MAF has failed.

004. Injectors You must log this block at idle for a few minutes. A snap shot tells you nothing.

1. Engine Speed,(G28). Idle 800 rpm.

2. Injection Start,(specified), Idle 0.0 °BTDC ... 5.0 °ATDC

3. Injection Duration,(specified), Idle 2.0...4.0 °CR

4. Torsion Value, -3...+3 °CR nearer to zero figure the better.

A log of 004 at idle for a few minutes should show. All values stable with little if any variation.

Variation suggests injector or camshaft problems.

005. Start Conditions (last Engine Start) This data block is only useful if you suspect crankshaft or camshaft sensor faults)

1. Engine Speed,(G28), Idle 800

2. Start Injection Quantity, 7.0...19.0 mg/Str.

3. Start Synchronisation

The value is the Sum of the individual Values below.

001 = Self Synchronisation Camshaft active

002 = Self Synchronisation Crankshaft active

004 = Engine running

008 = Engine Synchronisation validated

016 = Engine Synchronisation successful

032 = Self Synchronisation Camshaft-Sensor successful

064 = Self Synchronisation Crankshaft-Sensor successful

128 = First valid Tooth recognized

Most successful starts register as 255. (255 = 128 + 64 + 32 etc).

A failure of crank or cam sensor will cause a total with one or more numbers missing.

4. Coolant Temperature (G62), Warm 80.0...110.0 °C.

Pre B6 engines cannot run if the cranshaft sensor fails. B6 engines can continue to run.

006. Cruise Control System (CCS) You can use these figures to check the brake and clutch switches

1. Vehicle Speed,(actual) 0.0 km/h if the car is stationary

2. Pedal Monitoring

00000001 = Brake Light Switch operated

00000010 = Brake Pedal Switch operated

00000100 = Clutch Pedal Switch operated

00001000 = CCS enabled

00010000 = ACC enabled

00100000 = Main Switch

00000000 = ACC/CCS Mode not active

10000000 = Status override

01000000 = ACC/GRA active

11000000 = ACC blocked

3. Accelerator Pedal Position Sensor 1 (G79). Idle 0.0 %

4. Switch Monitoring. Idle 0

xxxxxxx? = Stuck ON

xxxxxx?x = Pressed OFF

xxxxx?xx = Decelerate (-)

xxxx?xxx = Accelerate (+)

xxx?xxxx = Set (SET)

xx?xxxxx = Resume (RESET)

?xxxxxxx = Stuck ON (Hardware)

007. Temperatures (Fuel, Coolant & Intake air temperatures should all match Ambient temperature when starting from cold).

1. Fuel Temperature,(G81), Cold = Ambient Temperature

3. Intake Air, Temperature (G72), Cold = Ambient Temperature

4. Coolant Temperature (G62), Cold = Ambient Temperature Expect 85 °C on a hot engine.

A fault will be flagged if any of these temperatures fail to be close to Ambient temperature at a cold start up.

A fault will be flagged if the coolant temperature fails to follow the expected ecu map as the engine warms up.

Generally: Fuel temp will remain slightly cooler than coolant temp across the range.

Air intake temp should match ambient temp but is often a little higher as the intercooler is not perfect.

008. Injection Quantity Limitation I (Torque Limitation)

1. Engine Speed,(G28),Idle 800 rpm.

2. Torque Request,(Driver), Idle -5.0...0.0 Nm.

3. Torque Limitation, Idle 100.0...200.0 Nm.

4. Smoke Limitation, Idle 100.0...200.0 Nm.

009. Injection Quantity Limitation II (Torque Limitation)

1. Engine Speed,(G28), Idle 800 rpm

2. Torque Request,(Cruise Control) -985…995 Nm

3. Transmission Limitation 1024.0 Nm

4. Torque Restriction 130…145 Nm

010. Charge Pressure Control

1. Mass Air Flow,(actual), Idle 300…400.0 mg/Stroke.

2. Atmospheric Pressure. roughly 1000.0 mbar

3. Boost Pressure,(actual), Idle 1000.0 m/bar mbar (no boost). Full Load 2000.0...2500.0 mbar

4. Accelerator Pedal Position Sensor 1 (G79), Idle 0.0 % Maximum100.0 %

011. Charge Pressure Control

To test boost function you must log 011 from idle to 3500 rpm.

1. Engine Speed (G28) Idle 800 rpm

2. Boost Pressure (specified), Idle 1000.0 mbar Full Load 2100.0...2500.0 mbar

3. Boost Pressure (actual), Idle 1000.0 mbar Full Load 2000.0...2500.0 mbar

Boost actual is often higher than boost specified. If the difference is too great the turbo will be switched off by the ecu (limp mode).

4. Charge Pressure Control Duty Cycle, Idle 80.0...85.0 % Full Load 80.0...20.0 % (% should drop as rpm rise)

The charge pressure duty cycle should not go above 85%. If it does, this is over boost and will register a fault code. (The turbo vanes are stuck full open).

The full load drop down from 80% is the turbo vanes closing.

This graph is for a 1.9 tdi.

The specified boost starts from 1300 rpm and increase rapidly to 2000 rpm where it reaches 2000 mbar.

The actual boosts starts at 1300 rpm and follows the specified boost but “over shoots” to 2400 mbar at 2100 rpm. (This is normal). The “over boost” is corrected and the boost drops to remain in line with the specified boost.

The 2.0 pd engine has a similar boost graph but the boost does not start until later in the rpm band. (Approximately 2400 rpm)

012. Glow Plugs

1. Glow Status Hot engine 11111111 (OFF)

00000000 = Waiting for Coolant Temperature

00000001 = Waiting for ECO Start Request

00010000 = Pre-Glow

01010000 = No Pre-Glow

10110000 = Post-Glow

11000000 = No Post-Glow

11110000 = Interim Glow

00110000 = Readiness Glowing

01110000 = Glow Start

10110001 = Waiting for Post-Glow

11010000 = No Post-Glow

11110001 = Waiting for Interim Glow

11111111 = Glowing OFF

2. Pre-Glow Period. 0.0s

3. Supply Voltage,(Terminal 30). 13.0...15.0 V

4. Coolant Temperature (G62). Hot 80.0...110.0 °C

013. Idle Stabilization (Injection Quantity Deviation)

1. Injection Quantity Deviation Cylinder 1, Idle -1.0...+1.0 mg/Str.

2. Injection Quantity Deviation Cylinder 2, Idle -1.0...+1.0 mg/Str.

3. Injection Quantity Deviation Cylinder 3, Idle -1.0...+1.0 mg/Str.

4. Injection Quantity Deviation Cylinder 4, Idle -1.0...+1.0 mg/Str.

These figures vary very little if the injectors and cam lobes are good.

015. Fuel Consumption

1. Engine Speed,(G28), Idle 800 rpm.

2. Engine Torque, Idle 25.0...50.0 Nm

3. Fuel Consumption Idle 0.2…1.5 l/h

4. Torque Request (Driver), Idle -5.0...0.0 Nm

016. Auxiliary Heating

1. Generator Load 30.0...95.0 %

4. Supply Voltage, (Terminal 30), Specification: 13.0...15.0 V

017. Readiness Code (EOBD)

1. CARB, Mode 01 DATA A

x---0000 = No Fault Codes stored

0---xxxx = MIL OFF

1---xxxx = MIL ON

2. CARB, Mode 01 DATA B

-xxx-xx1 = Activation Misfire Recognition OIN

-xxx-x1x = Activation Fuel Supply System ON

-xxx-1xx = Activation Comprehensive Components ON

-xxx-xxx = EOBD-Test Misfire Recognition finished

-x0x-xxx = EOBD-Test Fuel Supply System finished

-0xx-xxx = EOBD-Test Comprehensive Components finished

3. CARB, Mode 01 DATA C

xx1----- = Activation Oxygen/Lambda Sensor ON

x1x----- = Activation Oxygen/Lambda Sensor Heating ON

1xx----- = Activation Exhaust Gas Recirculation (EGR) ON

4. CARB, Mode 01 DATA D

xx0----- = EOBD-Test Oxygen/Lambda Sensor finished

x0x----- = EOBD-Test Oxygen/Lambda Sensor Heating finished

0xx----- = EOBD-Test Exhaust Gas Recirculation (EGR) finished

018. Injector Status

1. Injector Status, Cylinder 1. 000

2. Injector Status, Cylinder 2. 000

3. Injector Status, Cylinder 3. 000

4. Injector Status, Cylinder 4. 000

The code is the sum of any of the fault codes below.

000 = No Faults detected

002 = Control while Starting

004 = Small Injection Quantity or Injector faulty

008 = Maximum Current reached

016 = Begin of Injection Period (BIP) out of Specification

032 = Samples too low

064 = Conversion Error

128 = Begin of Injection Period (BIP) not possible

019. Piezo Injector Voltage

1. 130 V…150 V

2. 130 V…150 V

3. 130 V…150 V

4. 130 V…150 V

These voltages don’t seem to help with diagnostics. (A faulty injector usually registers as a short to + or short to -)

020. Injection Quantity Limitation (from ABS)

1. Engine Speed,(G28), Idle 800 rpm

2. Engine Torque Idle 20.0…50.0 Nm

3. ASR Limitation Idle 1024 Nm Value high as wheels not turning

4. MSR Limitation Idle 0.0 Nm Value low as engine not reving in comparison to stationary wheels

021. CAN-Databus Status (Powertrain)

1. Engine Electronics

2. Transmission Electronics

3. Brake Electronics

4. Brake Electronics (ESP)

022. Shut-Off Status

1. Shut-Off Status, Cruise Control

2. Switch Monitoring, Cruise Control

000 = Neutral

001 = OFF (Switched)

002 = OFF (Tipped)

003 = SET (CCS ON)

004 = Tip Down

005 = Deceleration (-)

006 = RESUME/RESET

007 = Tip Up

008 = Acceleration (+)

3. Shut-Off Status, Charge Pressure

001 = Cold Start

002 = System Malfunction

004 = Control Deviation

016 = Diagnostic Interference

4. Shut-Off Status, Climate Control

001 = Launch Condition

002 = Shut-Off: Launch Condition

004 = Acceleration Condition

008 = Shut-Off: Acceleration Condition

016 = Shut-Off: Start Condition

032 = System Malfunction recognized

064 = Shut-Off: System Malfunction recognized

128 = Shut-Off: Idle Speed too Low

023. Injector Switch Time Deviation

1. Switch Time Deviation, Cylinder 1. -0.25...+0.25 ms

2. Switch Time Deviation, Cylinder 2. -0.25...+0.25 ms

3. Switch Time Deviation, Cylinder 3. -0.25...+0.25 ms

4. Switch Time Deviation, Cylinder 4. -0.25...+0.25 ms

025. Engine Speed

1. Engine Speed,(G28),Specification (Idle): 800 rpm. Full Load 3200 rpm

2. Terminal 50 status.

3. Engine status.

4. Start cancel conditions.

026. Checksum

028. Accelerator Pedal Position Sensor

1. Accelerator Pedal Position, Sensor 1 (G79), 0 % = 0.75…0.76 V. 100 % = 3.80...4.94 V

2. Accelerator Pedal Position, Sensor 2 (G185), 0 % = 0.37...0.38 V. 100 % = 1.90...2.58 V

3. Operation Status

xxxxxxx1 = Climate Control ON

xxxx1xxx = Idle Switch closed

xxx1xxxx = Kick-Down (only Automatic Transmission)

x1xxxxxx = Idle Speed raised

4. Accelerator Pedal Position Sensor 1 (G79), Idle 0.0 %. Maximum 100.0 %.

029. Temperature and Oil Level Sensor (TOG)

1. Oil Temperature. Same as coolant (roughly)

2. Oil Level 24…30 mm

3. Wear Index 0

4. Soot Index 0

051. Engine Speed Recognition

1. Engine Speed Idle 800 rpm

2. Camshaft Speed Specification: Engine Speed/2 = ± 50 rpm Expect 400 rpm roughly.

3. Start Synchronisation Normal start = 255

Value is sum of values below.

000 = Basic Initialisation

001 = Counter Reset

002 = Engine Standstill OR Malfunction

003 = Transition States

004 = Plausibility Phase

005 = Plausibility Phase

006 = Plausibility Phase

008 = Plausibility Phase

016 = Phase Determination

028 = Redundant Start

032 = Synchronisation Phase

033 = System Positioning

048 = Sequential Counter activated

064 = System waiting for Engine Standstill

128 = Dynamic Plausibility

4. Shut-Off Status, Injection Sequence 00000000.

062. Engine Cooling (Temperatures)

1. Coolant Temperature, Engine Output, Hot . 85.0 °C +

2. Coolant Temperature, Cooler Output, Hot . 85.0 °C +

3. Ambient Temperature, Range -30.0...+50.0 °C

4. Intake Air Temperature, Range 5.0...80.0 °C Expect roughly the same as the ambient temp.

The engine ecu contains a built in map for engine warm up. The engine coolant should heat up as in the graph above. Failure to follow this warm up pattern will set a fault code. When hot the coolant should be above 85 °C. (The thermostat set point is 88 °C)

The temperature MUST be above 80 °C.

If the temperature seems too high or too low it could be a faulty temperature sensor. This is not likely on a B6, as the engine ecu should spot that and flag a code.

If the temperature seems too high it could be a faulty water pump or the thermostat is not opening properly.

If the temperature is too low, the thermostat may be staying open more than it should.

063. Engine Cooling (Climate Control)

1. Refrigerant Pressure A/C. OFF = 0.00...8.00 bar. A/C ON = 5.00...30.00 bar

2. Load Torque, Specification. A/C OFF = 0 Nm. A/C ON = 2...10 Nm

3. Cooling Request. Off = 0.0 %

4. Shut-Off Status, Climate Control 00000000 means no problems assuming it is off.

001 = Launch Condition

002 = Shut-Off: Launch Condition

004 = Acceleration Condition

008 = Shut-Off: Acceleration Condition

016 = Shut-Off: Start Condition

032 = System Malfunction recognized

064 = Shut-Off: System Malfunction recognized

128 = Shut-Off: Idle Speed too Low

064. Engine Cooling

1. Coolant Temperature (G62), Hot 80.0...110.0 °C 85 °C

2. Coolant Temperature, Cooler Output, 85.0 °C

3. Coolant Fan 1, Duty Cycle, Fan. OFF = 8.0...9.0 %. Fan ON = 10.0...100.0 %

080. Advanced Control Module Identification I

081. Advanced Control Module Identification II

1. Vehicle Identification Number (VIN) This is the VIN for your car.

082. Advanced Control Module Identification III

086. EOBD

087. EOBD

090. EOBD/OBD-2 Exhaust Gas Recirculation (EGR) I

1. Engine Speed,(G28), Idle 800 rpm.

2. Injection Quantity, Idle 3.0...7.0 mg/Stroke.

3. Exhaust Gas Recirculation. (specified.), Idle Expect 300…400 mg/Stroke.

4. Status Control Deviation No faults = 00000000

Blocks 125 – 129 are CAN communication checks.

Only control modules fitted to the car will show.

If communication with that module is ok = 1. Not ok = 0

E.g. ABS 1 means Brake electronics control module communication ok.

125. CAN-Databus Communication (Powertrain)

1. Transmission Transmission 1 for an automatic

2. Brake Electronics (J104), ABS 1

3. Instrument Cluster (J285), Instruments 1

4. Airbag (J234), Airbag 1

126. CAN-Databus Communication (Powertrain)

1. Climate Control (J255), HVAC 1

127. CAN-Databus Communication (Powertrain)

3. Electronic Ignition Lock. (J764), El.Ign.Lock 1

4. Steering Wheel, Electronics (J527), St Wheel 1

128. CAN-Databus Communication (Powertrain)

1. CAN-Gateway (J533), Gateway 1

4. Park Brake Control. (J540), Park Brake 1

Blocks 225 – 228 are communication time out checks ??????

Expect 0 from all modules present.

225. CAN-Databus Timeout (Powertrain)

1. Transmission 0

2. Brake Electronics (J104) 0

3. Instrument Cluster (J285) 0

4. Airbag (J234) 0

226. CAN-Databus Timeout (Powertrain)

1. Climate Control (J255) 0

227. CAN-Databus Timeout (Powertrain)

3. Electronic Ignition Lock. (J764) 0

4. Steering Wheel, Electronics (J527) 0

228. CAN-Databus Timeout (Powertrain)

1. CAN-Gateway (J533) 0

4. Park Brake Control. (J540), 0

GLOSSARY

Mg = milligrams.

Str = Engine Stroke

°CR = Degree Crankshaft Rotation

°C = Degree Celcius

rpm = Engine revolutions per minute

BTDC = Before Top Dead Center

ATDC = After Top Dead Center

Nm = Newton metres (Torque)

Mbar = Millibar (pressure)

V = Volts

EOBD = European On Board Diagnostics

ASR = Traction control (Anti wheel spin via ABS)

MSR = Engine Torque control (Anti wheel spin via engine ecu)