new $EE tuning thing!

[Terminal_Crazy]

CCM Module:

This has the F0 56 message ... F0 Poll (CCM ALDL Device Presence check )




DATA STREAM A297 SPECIFICATION






..PAGE
SPECIFICATIONS FOR DATA STREAM INFORMATION
-------------------------------------------

CCM USAGE:
1995 "Y" CAR WITH 5.7L (LT1) (VIN=P) AND 5.7L (LT5) (VIN=J)




DATA PIN : READ DATA ON PIN "9" OF ALDL CONNECTOR

BAUD RATE : 8192 BAUD - BI-DIRECTIONAL

..END
MODE 0 (RETURN TO NORMAL MODE)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $56
- MODE = $00
- CHECKSUM


F0 POLL (CCM ALDL DEVICE PRESENCE CHECK)
- MESSAGE ID = $F0
- MESSAGE LENGTH = $56
- CCM ID = $F1
- CHECKSUM



MODE 1 (TRANSMIT MESSAGE 0)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $57
- MODE = $01
- MESSAGE NUMBER = $00
- CHECKSUM

THE CCM RESPONDS WITH THE FOLLOWING MESSAGE:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $7A
- MODE = $01
- DATA BYTE 1
.
.
- DATA BYTE 36
- CHECKSUM

MODE 1 (TRANSMIT MESSAGE 1)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $57
- MODE = $01
- MESSAGE NUMBER = $01
- CHECKSUM

THE CCM RESPONDS WITH THE FOLLOWING MESSAGE:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $6D
- MODE = $01
- DATA BYTE 1
.
.
- DATA BYTE 23
- CHECKSUM

MODE 7 (COMMAND MESSAGE)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $57
- MODE = $07
- MESSAGE CODE = $10
- CHECKSUM

THE CCM RESPONDS BY TRANSMITTING THE NORMAL MODE MESSAGE



MODE 8 (DISABLE COMMUNICATIONS)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $56
- MODE = $08
- CHECKSUM



MODE 9 (ENABLE COMMUNICATIONS)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $56
- MODE = $09
- CHECKSUM


MODE 10 (CLEAR MALFUNCTION CODES)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $56
- MODE = $0A
- CHECKSUM



..PAGE
..HEAD02L CCM ALDL DATA LIST
..HEAD03L NUMBER OF DATA WORDS - 36
..HEAD04L CCM ALDL MODE 1 DATA LIST (MESSAGE 0)
BYTE BIT DESCRIPTION
---- --- -------------
1 0-2 UNIVERSAL THEFT DETERRENT STATE
0 = PASSIVE
1 = ACTIVE
2 = DOORS ARMED
3 = DOORS AND HATCH ARMED
4 = ALARM
5 = ALARM TIMED OUT
3 FEDS FUEL ENABLE 0 = DISABLE 1 = ENABLE
4 ENGLISH/METRIC STATUS 0 = ENGLISH 1 = METRIC
5 CURRENT FAULT 0 = NO 1 = YES
6 NOT USED
7 NOT USED

2 0 DOOR KEY SWITCH 0 = NORMAL 1 = UNLOCK
1 RIGHT DOOR AJAR 0 = CLOSED 1 = OPEN
2 LEFT DOOR AJAR 0 = CLOSED 1 = OPEN
3 KEY IN IGNITION 0 = NO 1 = YES
4 HATCH AJAR 0 = CLOSED 1 = OPEN
5 POWER DOOR UNLOCK 0 = NO 1 = YES
6 POWER DOOR LOCK 0 = NO 1 = YES
7 NOT USED

3 0 PARKING LIGHTS 0 = OFF 1 = ON
1 REAR DEFOG 0 = OFF 1 = ON (90MS ON PUSLE)
2 SEAT BELT SWITCH 0 = OFF 1 = ON
3 HIGH BEAM 0 = OFF 1 = ON
4 NOT USED
5 OIL LEVEL SWITCH 0 = LOW 1 = NORMAL
6 NOT USED
7 NOT USED

4 0 IGNITION 3 PRESENT 0 = NO 1 = YES
1 IGNITION 1 PRESENT 0 = NO 1 = YES
2 DIAGNOSTIC ENABLE 0 = DISABLE 1 = ENABLE
3 NOT USED
4 FASTEN SEAT BELTS INPUT 0 = INACTIVE 1 = ACTIVE
5 NOT USED
6 NOT USED
7 NOT USED

5 0 CHANGE OIL TELLTALE 0 = OFF 1 = ON
1 CHECK GAGES TELLTALE 0 = OFF 1 = ON
2 FASTEN SEAT BELT TELLTALE 0 = OFF 1 = ON
3 SECURITY LAMP TELLTALE 0 = OFF 1 = ON
4 DELAYED ACCESSORY BUS 0 = OFF 1 = ON
5 HIGH BEAM INDICATOR DIM 0 = 60% 1 = 100%
6 OIL LEVEL TELLTALE 0 = OFF 1 = ON
7 DOOR AJAR TELLTALE 0 = OFF 1 = ON

6 0 LCD BLANKING CONTROL 0 = OFF 1 = ON
1 HORN RELAY 0 = OFF 1 = ON
2 REAR DEFOG RELAY 0 = OFF 1 = ON
3 COURTESY LAMP RELAY 0 = OFF 1 = ON
4 CRANK RELAY 0 = OFF 1 = ON
5 CHIME 0 0 = OFF 1 = ON
6 CHIME 1 0 = OFF 1 = ON
7 NOT USED

7 0 LCD BLANKING CONTROL-FDBK 0 = OFF 1 = ON
1 HORN RELAY-FDBK 0 = OFF 1 = ON
2 REAR DEFOG RELAY-FDBK 0 = OFF 1 = ON
3 COURTESY LAMP RELAY-FDBK 0 = OFF 1 = ON
4 CRANK RELAY-FDBK 0 = OFF 1 = ON
5 NOT USED
6 NOT USED
7 NOT USED

8 DIC SWITCH A/D COUNTS N = COUNTS (SEE TABLE 1)
9 UNFILTERED FUEL LEVEL GAL = N*.1
10 FILTERED DIMMING POTENTIOMETER N = COUNTS
11 VATS KEY A/D COUNTS N = COUNTS (SEE TABLE 2)
12 AMBIENT LIGHT SENSOR A/D COUNTS N = COUNTS
13 VEHICLE SPEED MPH = N
KPH = N*1.609
14 IGNITION 1 VOLTAGE VOLTS = N*.1
15 SWITCHED BATTERY VOLTAGE VOLTS = N*.1
16 CLUSTER GAGE BACKLIGHT DIMMING PWM %DUTY CYCLE = N
17 CLUSTER LCD BACKLIGHT DIMMING PWM %DUTY CYCLE = N
18 HVAC AND RADIO LCD BACKLIGHT DIMMING %DUTY CYCLE = N
19 LED INDICATOR DIMMING PWM %DUTY CYCLE = N
20 SEASON ODOMETER MSB
21 SEASON ODOMETER LSB MILES = ([N20]*250+[N21])*16
22 OIL MONITOR EFFECTIVE REVOLUTION TO SERVICE COUNTER
REVOLUTIONS = N*100,000
23 REAR DEFOG TIMER SECONDS = N*5
24 COURTESY LAMP TIMER SECONDS = N

25 CURRENT MALFUNCTION WORD 1
0 MALF CODE 22 1 = DEFOG RELAY COIL SHORT-BAT/OPEN CCM
1 MALF CODE 21 1 = HORN RELAY COIL SHORT-BAT/OPEN CCM
2 NOT USED
3 MALF CODE 16 1 = IGNITION 3 FUSE BLOWN OR MISSING
4 MALF CODE 15 1 = FUEL LEVEL SENSOR OPEN/SHORT TO BAT
5 MALF CODE 14 1 = DIC SWITCH SHORTED TO GROUND
6 MALF CODE 13 1 = DIC SWITCH OPEN/SHORT TO BAT
7 MALF CODE 12 1 = NO MALFUNCTION CODE STORED

26 CURRENT MALFUNCTION WORD 2
0 MALF CODE 31 1 = LCD DATA SHORT TO BAT/OPEN CCM
1 NOT USED
2 NOT USED
3 MALF CODE 27 1 = LCD BLANKING CTL SHORT TO GND/OPEN
4 MALF CODE 26 1 = LCD BLANKING CTL SHORT-BAT/OPEN CCM
5 MALF CODE 25 1 = CTSY RELAY COIL SHORT TO GND/OPEN
6 MALF CODE 24 1 = CTSY RELAY COIL SHORT-BAT/OPEN CCM
7 MALF CODE 23 1 = DEFOG RELAY COIL SHORT IT GND/OPEN
27 CURRENT MALFUNCTION WORD 3
0 NOT USED
1 MALF CODE 38 1 = M CLOCK SHORT TO GND/OPEN
2 MALF CODE 37 1 = M CLOCK SHORT-BAT/OPEN CCM
3 MALF CODE 36 1 = DATA STROBE SHORT TO GND/OPEN
4 MALF CODE 35 1 = DATA STROBE SHORT-BAT/OPEN CCM
5 MALF CODE 34 1 = DATA CLOCK SHORT TO GND/OPEN
6 MALF CODE 33 1 = DATA CLOCK SHORT-BAT/OPEN CCM
7 MALF CODE 32 1 = LCD DATA SHORT TO GND/OPEN
28 CURRENT MALFUNCTION WORD 4
0 MALF CODE 54 1 = VATS FUEL ENABLE FAILURE
1 MALF CODE 53 1 = VATS OPEN KEY CIRCUIT DETECTION
2 MALF CODE 52 1 = VATS SHORTED KEY CIRCUIT DETECTION
3 MALF CODE 51 1 = VATS INVALID KEY DETECTION
4 NOT USED
5 NOT USED
6 MALF CODE 42 1 = LOSS OF ABS/ASR SERIAL DATA
7 MALF CODE 41 1 = LOSS OF ECM SERIAL DATA

29 CURRENT MALFUNCTION WORD 5
0 NOT USED
1 NOT USED
2 NOT USED
3 MALF CODE 63 1 = VATS KEY #2 RESISTANCE TOO LOW
4 MALF CODE 62 1 = VATS KEY #2 RESISTANCE TOO HIGH
5 MALF CODE 61 1 = VATS KEY #1 RESISTANCE OUT OF RANGE
6 NOT USED
7 NOT USED

30 CURRENT MALFUNCTION WORD 6
0 MALF CODE 81 1 = INVALID VEHICLE CONFIGURATION DETECTED
1 NOT USED
2 NOT USED
3 MALF CODE 74 1 = LED DIM PWM OUTPUT SHORT TO GND/OPEN
4 MALF CODE 73 1 = LED DIM PWM OUTPUT SHORT-BAT/OPEN CCM
5 MALF CODE 72 1 = VF DIM PWM OUTPUT SHORT TO GND/OPEN
6 MALF CODE 71 1 = VF DIM PWM OUTPUT SHORT-BAT/OPEN CCM
7 NOT USED

31 HISTORY MALFUNCTION WORD 1
0 HIST MALF CODE 22 1 = DEFOG RELAY COIL SHORT-BAT/OPEN CCM
1 HIST MALF CODE 21 1 = HORN RELAY COIL SHORT-BAT/OPEN CCM
2 NOT USED
3 HIST MALF CODE 16 1 = IGNITION 3 FUSE BLOWN OR MISSING
4 HIST MALF CODE 15 1 = FUEL LEVEL SENSOR OPEN/SHORT TO BAT
5 HIST MALF CODE 14 1 = DIC SWITCH SHORTED TO GROUND
6 HIST MALF CODE 13 1 = DIC SWITCH OPEN/SHORT TO BAT
7 HIST MALF CODE 12 1 = NO MALFUNCTION CODE STORED

32 HISTORY MALFUNCTION WORD 2
0 HIST MALF CODE 31 1 = LCD DATA SHORT TO BAT/OPEN CCM
1 NOT USED
2 NOT USED
3 HIST MALF CODE 27 1 = LCD BLANKING CTL SHORT TO GND/OPEN
4 HIST MALF CODE 26 1 = LCD BLANKING CTL SHORT-BAT/OPEN CCM
5 HIST MALF CODE 25 1 = CTSY RELAY COIL SHORT TO GND/OPEN
6 HIST MALF CODE 24 1 = CTSY RELAY COIL SHORT-BAT/OPEN CCM
7 HIST MALF CODE 23 1 = DEFOG RELAY COIL SHORT IT GND/OPEN
..page
33 HISTORY MALFUNCTION WORD 3
0 NOT USED
1 HIST MALF CODE 38 1 = M CLOCK SHORT TO GND/OPEN
2 HIST MALF CODE 37 1 = M CLOCK SHORT-BAT/OPEN CCM
3 HIST MALF CODE 36 1 = DATA STROBE SHORT TO GND/OPEN
4 HIST MALF CODE 35 1 = DATA STROBE SHORT-BAT/OPEN CCM
5 HIST MALF CODE 34 1 = DATA CLOCK SHORT TO GND/OPEN
6 HIST MALF CODE 33 1 = DATA CLOCK SHORT-BAT/OPEN CCM
7 HIST MALF CODE 32 1 = LCD DATA SHORT TO GND/OPEN

34 HISTORY MALFUNCTION WORD 4
0 HIST MALF CODE 54 1 = VATS FUEL ENABLE FAILURE
1 HIST MALF CODE 53 1 = VATS OPEN KEY CIRCUIT DETECTION
2 HIST MALF CODE 52 1 = VATS SHORTED KEY CIRCUIT DETECTION
3 HIST MALF CODE 51 1 = VATS INVALID KEY DETECTION
4 NOT USED
5 NOT USED
6 HIST MALF CODE 42 1 = LOSS OF ABS/ASR SERIAL DATA
7 HIST MALF CODE 41 1 = LOSS OF ECM SERIAL DATA

35 HISTORY MALFUNCTION WORD 5
0 NOT USED
1 NOT USED
2 NOT USED
3 HIST MALF CODE 63 1 = VATS KEY #2 RESISTANCE TOO LOW
4 HIST MALF CODE 62 1 = VATS KEY #2 RESISTANCE TOO HIGH
5 HIST MALF CODE 61 1 = VATS KIY #1 RESISTANCE OUT OF RANGE
6 NOT USED
7 NOT USED

36 HISTORY MALFUNCTION WORD 6
0 HIST MALF CODE 81 1 = INVALID VEHICLE CONFIGURATION DETECTED
1 NOT USED
2 NOT USED
3 MALF CODE 74 1 = LED DIM PWM OUTPUT SHORT TO GND/OPEN
4 MALF CODE 73 1 = LED DIM PWM OUTPUT SHORT-BAT/OPEN CCM
5 HIST MALF CODE 72 1 = VF DIM PWM OUTPUT SHORT TO GND/OPEN
6 HIST MALF CODE 71 1 = VF DIM PWM OUTPUT SHORT-BAT/OPEN CCM
7 NOT USED


..PAGE
..HEAD02L CCM ALDL DATA LIST
..HEAD03L NUMBER OF DATA WORDS - 23
..HEAD04L CCM ALDL MODE 1 DATA LIST (MESSAGE 1)
BYTE BIT DESCRIPTION
---- --- -----------
1 FIRST PROM ID WORD (MSB)
2 SECOND PROM ID WORD (LSB)
3-19 VEHICLE IDENTIFICATION NUMBER

20 0 REAL TIME DAMPING 0 = NO 1 = YES
1 ANTI-LOCK BRAKES 0 = NO 1 = YES
2 ELECTRONIC THROTTLE CONTROL 1 = YES
3 RESERVE FUEL INDICATION 0 = NO 1 = YES
4 OVERSPEED WARNING 0 = YES 1 = NO
5 SPEEDOMETER BIASING 0 = YES 1 = NO
6 ROUGH ROAD DETECTION 0 = NO 1 = YES
7 NOT USED

21 0 ENGINE 0 = LT1 1 = LT5
1 TRANSMISSION 0 = AUTO 1 = MANUAL
2 MAGNETIC SPEED-DEPENDANT VARIABLE ASSIT 1 = PRESENT
3 HVAC 0 = C60 1 = C68
4 LOW TIRE PRESSURE WARINING SYSTEM 1 = PRESENT
5 SELECTIVE RIDE SYSTEM 1 = PRESENT
6 POWER SEAT, DIRVER SIDE 1 = PRESENT
7 POWER SEAT, PASSENGER SIDE 1 = PRESENT

22 0 NOT USED
1 NOT USED
2 NOT USED
3 NOT USED
4-7 NOT USED

23 0-7 NOT USED

[spfautsch]

Sweet, thanks! This gives me a few ideas.

I guess I'm going to try sending it a mode 08 and see what happens. Being a slave I can't imagine it will have any effect, and there was no mention of mode 08 in the ABS section.

This is interesting.

7 ASR State 1 = active 0 = passive
6 Brake Light Switch State 1 = on 0 = off
5 ABS state 1 = active 0 = passive
4 ASR switched off by driver 1 = yes 0 = no

Guessing "active" ASR is where it uses the throttle control module and rear brakes to intervene with wheelspin.

Another thought that occurred just now is if the ALDL noise I'm seeing corresponding to wheel slippage is the ABS module sending timing retard requests to the ECM. Though I would have assumed a dedicated input pin would have been used for that instead of pumping the data over the serial bus.

[steveo]

it is done on a seperate line for sure, but that's not to say there isn't an accompanying aldl message for another purpose.

[lionelhutz]

The timing retard is a dedicated PWM signal between the ABS and PCM. The speed and accuracy of the timing cut signal goes beyond what the ALDL can accomplish.

The ALDL stuff you see would be to display a message or light the light in the cluster or something like that.

[spfautsch]

The ALDL stuff you see would be to display a message or light the light in the cluster or something like that.

That makes sense.

Sending mode 08 to the ABS module gave me a much cleaner logging session with the "service ABS" light on. The serial errors I noticed seemed to mostly happen after hitting some bumps, so I'm going to start looking for loose grounds around the ABS and under the hood.

I'm going forward coding with the assumption that the b-bodies did not have an option for ASR / traction control. Would anyone know if that's a safe assumption or should I consider making "silence ABS module" a multi-body option?

[steveo]

i know on the fbody, it doesn't speak unless it's spoken to... and i think the bbody module is the same. silencing it wouldn't hurt anything anyways. on the f-body, the "traction control" light is a hardware thing, doesn't use the aldl bus

once i have your working code in my hands i'll probably abstract things even further then push it into beta and get some b-body guys testing. that way we can have a cookie cutter connection method for all three vehicle types which can improve as we go.

it'd be nice if there was a way to determine beyond a shadow of a doubt if modules ever push notifications to the aldl stream even without a heartbeat, but it's undocumented, so logging or hacking the module apart are the only ways... i doubt it's common practice, but errors in the datastream often make me go 'hmm' since they really shouldn't happen beyond actual electrical noise.

we really need to keep the vehicle type selector regardless, i need that branching for the next generation of definition file (which will allow us to have vehicle-specific module readouts for sir/abs/etc), and that can't be runtime configurable anyway, so that gives us the opportunity to make each method of initial connection and its maintenance super optimal.

[spfautsch]

Sent you some diffs, check your PMs.

I left the body selector more or less alone because if the ECM is bus master on the b-bodys it's important to silence things in the correct order. There's nothing happening in the f-body branch in the silence routine because the first thing I'm doing is a mode 08 to the ECM for all body types.

I suspect there's a "barge in" mechanism the ABS/EBTCM uses to squelch comms on the ALDL. But I've also noticed a few VSS errors in my logs so it could be electrical noise. My bucket has almost 160,000 miles and has been worked on by some genuine idiots. When I first got underneath I found a large bundle of ground eyelets unconnected and electrical taped to a body strut under the drivers side rear by where the power antenna used to live.

[kur4o]

B-bodies are same as F-body, the main difference is, there is much more idle traffic sent from PCM.
B and F has digital traction control. All request are handled through aldl communication.
Traction request spark retard by sending aldl frame and frequency signal at pin a23 to PCM

Y-body traction is an analog system with simple on off request. Pcm [pin a12] sends pwm signal for TPS % to traction. Traction request Spark retard from PCM by grounding pin c12
PCM hadles the spark retard only.

Y-bodies are completely different. Pcm has zero idle traffic. All the idle traffic is sent from ccm. PCM only responds to ccm request.
[F0 56 F1 C9] ccm send aldl broadcast message with F1 id
[10 59 08 4F 02 00 3E ] this is some mistery frame send from ccm probably to module with $10 ID
[40 57 FF FF 6B ] CCM send mode 7 request to PCM
[41 67 02 F2 00 4F 4E 01 00 46 1A C3 88 00 42 FF FF 00 A0 A0 9B ] PCM answer to CCM

You can see what is in the frame here
RESERVED:F343 fdb off_F371 ; UNKNOWN MODE 07 MSG 07 COMMMAND
RESERVED:F345 fcb $40 ; @ ; ALDL INSTUMENT PANEL 2 Y
RESERVED:F346 fcb $41 ; A
RESERVED:F347 fcb $80 ; À
RESERVED:F348 fcb $12
RESERVED:F349 fdb $1992
RESERVED:F34B fdb $1992
RESERVED:F34D fdb byte_156 ; UNKNOWN MODE ??? memory
RESERVED:F34F fdb byte_108
RESERVED:F351 fdb byte_176
RESERVED:F353 fdb word_1A2
RESERVED:F355 fdb byte_256
RESERVED:F357 fdb byte_9E
RESERVED:F359 fdb byte_9F
RESERVED:F35B fdb byte_182D
RESERVED:F35D fdb word_182B
RESERVED:F35F fdb word_182B+1
RESERVED:F361 fdb unk_3B00
RESERVED:F363 fdb byte_19D
RESERVED:F365 fdb word_1BD
RESERVED:F367 fdb word_1983
RESERVED:F369 fdb word_1983+1
RESERVED:F36B fdb word_1B16 ; ADR #7 AD filtered ?? TRANSM TEMP
RESERVED:F36D fcb 0
RESERVED:F36E fcb 0
RESERVED:F36F fcb 0
RESERVED:F370 fcb 0




to see what idle traffic is send by PCM check this cal data
This is from F-body cal

RESERVED:3AC7 fdb off_F253 ; MODE 7 IDLE TRAFFIC LOAD 16 pointers
RESERVED:3AC9 fdb 0
RESERVED:3ACB fdb 0
RESERVED:3ACD fdb 0
RESERVED:3ACF fdb off_F2B7 ; TRACTION ALDL MODE
RESERVED:3AD1 fdb 0
RESERVED:3AD3 fdb 0
RESERVED:3AD5 fdb 0
RESERVED:3AD7 fdb off_F2CB
RESERVED:3AD9 fdb 0
RESERVED:3ADB fdb 0
RESERVED:3ADD fdb 0
RESERVED:3ADF fdb off_F2B7 ; TRACTION ALDL MODE
RESERVED:3AE1 fdb 0
RESERVED:3AE3 fdb 0
RESERVED:3AE5 fdb 0


On y-body is all zeroed and there is no idle traffic from PCM
On b-body the data sent is much more.

I also have some request for you guys to patch eehack raw module.
When I try to send empty message it adds some extra byte.
I want to send [Id address] [message lenght] [checksum] with no data byte.

[Terminal_Crazy]

Y-bodies are completely different. Pcm has zero idle traffic. All the idle traffic is sent from ccm. PCM only responds to ccm request.
[F0 56 F1 C9] ccm send aldl broadcast message with F1 id
[10 59 08 4F 02 00 3E ] this is some mistery frame send from ccm probably to module with $10 ID
[40 57 FF FF 6B ] CCM send mode 7 request to PCM
[41 67 02 F2 00 4F 4E 01 00 46 1A C3 88 00 42 FF FF 00 A0 A0 9B ] PCM answer to CCM

The only $10 $59 response i can see in the Datastreams is A111/DS 90-91 Y car .. That doesn't preclude it from other data streams ... just that I can't find anything matching in the files.



DATA STREAM A111 SPECIFICATION



SPECIFICATIONS FOR DATA STREAM INFORMATION

-------------------------------------------



CCM USAGE:

1990 "Y" CAR WITH 5.7L (L98) (VIN=8) AND 5.7L (LT5) (VIN=J)

1991 "Y" CAR WITH 5.7L (L98) (VIN=8) AND 5.7L (LT5) (VIN=J)





DATA PIN : READ DATA ON PIN "M" OF ALDL CONNECTOR



BAUD RATE : 8192 BAUD - BI-DIRECTIONAL



..PAGE

MODE 0 (RETURN TO NORMAL MODE)

ALDL REQUEST:

- MESSAGE ID = $F1

- MESSAGE LENGTH = $56

- MODE = $00

- CHECKSUM



CCM RESPONSE:

CCM BROADCAST MESSAGE

- MESSAGE ID = $10

- MESSAGE LENGTH = $59

- STATUS WORD

BIT DESCRIPTION

0 ENGLISH/METRIC STATUS 0 = ENGLISH 1 = METRIC

1 ENGINE 0 = L98 1 = LT5

2 A/C CLUTCH STATUS 0 = OFF 1 = ON

3 SPARE

4 SPARE

5 SPARE

6 SPARE

7 SPARE



- COOLANT TEMPERATURE

DEG C = N*.75 - 40

- ENGINE RPM

RPM = N*25

- VEHICLE SPEED

MPH = N

- CHECKSUM





NOTE: THE BROADCAST MESSAGE IS USED TO SUPPLY INFORMATION TO

RECEIVE ONLY REMOTE SYSTEMS.







CCM ALDL DEVICE PRESENCE CHECK

- MESSAGE ID = $F0

- MESSAGE LENGTH = $56

- CCM ID = $F1

- CHECKSUM







..PAGE


Mitch

[Terminal_Crazy]

Wrong

A297/DS 95 Y car 5.7

has the following


DATA STREAM A297 SPECIFICATION

..PAGE
SPECIFICATIONS FOR DATA STREAM INFORMATION
-------------------------------------------

CCM USAGE:
1995 "Y" CAR WITH 5.7L (LT1) (VIN=P) AND 5.7L (LT5) (VIN=J)


DATA PIN : READ DATA ON PIN "9" OF ALDL CONNECTOR

BAUD RATE : 8192 BAUD - BI-DIRECTIONAL

..END
MODE 0 (RETURN TO NORMAL MODE)
ALDL REQUEST:
- MESSAGE ID = $F1
- MESSAGE LENGTH = $56
- MODE = $00
- CHECKSUM


F0 POLL (CCM ALDL DEVICE PRESENCE CHECK)
- MESSAGE ID = $F0
- MESSAGE LENGTH = $56
- CCM ID = $F1
- CHECKSUM


Mitch

[kur4o]

CCM RESPONSE:

CCM BROADCAST MESSAGE

- MESSAGE ID = $10

- MESSAGE LENGTH = $59

- STATUS WORD

BIT DESCRIPTION

0 ENGLISH/METRIC STATUS 0 = ENGLISH 1 = METRIC

1 ENGINE 0 = L98 1 = LT5

2 A/C CLUTCH STATUS 0 = OFF 1 = ON

3 SPARE

4 SPARE

5 SPARE

6 SPARE

7 SPARE



- COOLANT TEMPERATURE

DEG C = N*.75 - 40

- ENGINE RPM

RPM = N*25

- VEHICLE SPEED

MPH = N

- CHECKSUM





NOTE: THE BROADCAST MESSAGE IS USED TO SUPPLY INFORMATION TO

RECEIVE ONLY REMOTE SYSTEMS.
Mitch

Great info

[10 59 08 4F 02 00 3E ] is indeed ccm broadcast message and it`s data structure matches.


You can see data is same as recieved from PCM.
41
67

02 rpm
F2 ad map
00 tps
4F coolant
4E mat
01 options 1
00 options 2
46
1A
C3
88 inj flow rate
00 mph
42 oil temp
FF tcnt
FF tcnt
00 ad trans temp
A0
A0

9B checksum
________________________________
10
59

08 option byte
4F coolant
02 rpm
00 mph

3E checksum