SECTION 4

FACTORY TEST MODE

1.0 SUBJECT

Factory Test Mode

2.0 SCOPE

The factory test mode is designed to provide a way to monitor/exercise ECMs inputs and outputs for use in manufacturing/production covers on test. It is independent of customer software algorithms and calibration values so that a production ECM test can be implemented prior to production.

3.0 SPECIFICATION

3.1 Factory Test Mode Enable Criteria

The factory test mode is enabled if the following criteria are satisfied following a system reset.

1.In factory test mode (3.9K resistor to ground on diagnostic request input)

2.PPSW voltage greater than 16V

3.Battery voltage less than 10V

Once the factory test mode is enabled, it will remain enabled as long as the factory test mode is requested on the diagnostic request input and no system reset occurs. (Note that if ignition is cycled off while in Mode 1 with COP 2 not being toggled, a power down reset will immediately occur).

As soon as the factory test mode is enabled, the following actions take place.

1.$AA stored in all nonvolatile RAM locations, if the ECM powers up in Mode 1.

2.16K Checksum of Pluggable Memory Calculated

3.2 Factory Test Mode Function

The factory test made is divided into three basic modes based on the state of Bits 1 and 0 of the FMD #1 input discrete word (inputs IDH2 and IDH1 respectively) at the time an ignition OFF to ON transition occurs. These modes are selected as shown below:

FMD #1 FMD #1

Bit 1 Bit 0

IDH2 IDH1

(3rd gear) (P/N)

0 0 Mode 1 - All off made

x 1 Mode 2 - I/O check mode

1 0 Mode 3 - Miscellaneous test mode

3.2.1 High Speed UART Serial Data Format (Reference XDE-5024)

The approach used for the high speed transmission is intended to be the same as that used in a UART system. A description follows:

3.2.1.1 Bit Format

A bit time shall be 122.07 microseconds 0.5%. This is equivalent to 8192 Baud. A high voltage state indicates a logic one condition and a low voltage state indicates a logic zero condition.

3.2.1.2 Word Format

A word consists of ten bit times. The first bit is a logic zero and is called the Start Bit. The last (tenth bit) in the word is always a logic one and is called the Stop Bit. The remaining eight center bits are data bits and are transmitted LSB first. A Start Bit inust always be preceded by at least one logic one bit time (either the stop bit of the preceding word or an Idle Line).

3.2.1.3 Message Format

Any and all data transmitted on the serial data bus must be part of a message. All messages must be of the following format:

• • Idle line
  • Message Identification Word (ID)
  • Message Length (35+N)
  • N Bytes of Data
  • Sum Check
  • Idle Line

3.2.1.3.1 Idle Line

Ten or more consecutive logic one bit times constitute an Idle Line. All receivers on the bus will use the occurrence of an Idle Line followed by a Start Bit to indicate the start of a message.

3.2.1.3.2 Message Identification Word

When used in a UART system, the first word of each message is a message Identification (ID) word. Each Message ID must be unique; therefore, all Message ID's must be assigned in the particular Applications Document. The total number of unique message ID's is limited to 254. ID's of $00 and $FF shall not be used in UART system. For Factory Test the identification word is $00.

3.2.1.3.3 Message Length Word

The message length word indicates the total number of data words in the remainder of the message plus 85 (decimal). The maximum number of data words within one message which can be transmitted by any transmitter is 64. Thus a valid message length word must lie in the range of 85 to 149. Many messages with no data words are possible; for such messages, the Message Length Word would contain the binary word 0101 0101 (MSB-LSB). This pattern has been selected because, under an abnormally severe noise environment, there is a higher probability that an erroneously received message will be detected as such.

3.2.1.3.4 Sum Check

The last word to be transmitted in a message is the two's complement of the sum of all the other words in the message, including the Message ID and message length words. Any carry-outs of this eight-bit word while it is being formed by both the transmitter and receivers shall be neglected. The two's complement is used so that if the receivers sum all the words in the message, then the result should be zero for a valid message.

3.2.1.2 Serial Data Output

The serial data streams output for each particular mode are shown below. It should be noted that this information represents the data bytes only. The identifier code ($00 for Factory Test) and number of bytes transmitted precede these data bytes and the checksum will follow the data bytes.

3.2.1.2.1 Mode 1

No serial data is output in Mode 1

3.2.1.2.2 Mode 2 and Mode 3

Data Byte Description

1 PROMIDA (Upper Byte)

2 PROMIDA (Lower Byte)

3 DATECODE (Upper Byte)

4 DATECODE (Lower Byte)

5 SEQNUMB (Upper Byte)

6 SEQNUMB (Lower Byte)

7 ROMSUM (Upper Byte)

8 ROMSUM (Lower Byte)

9 NVMSUM (Upper Byte)

10 NVMSUM (Lower Byte)

11 SAD CHANNEL AN0

12 SAD CHANNEL AN1

13 SAD CHANNEL ANZ

14 SAD CHANNEL AN3

15 SAD CHANNEL AN4 (Coolant A/D-alternating pull-ups

each 25 msec.)

16 SAD CHANNEL ANS

17 SAD CHANNEL AN6

18 SAD CHANNEL AN7

19 SAD CHANNEL AN8

20 SAD CHANNEL AN9-0

21 SAD CHANNEL AN9-l

22 SAD CHANNEL AN9-2

23 SAD CHANNEL AN9-3

24 SAD CHANNEL AN9-4

25 SAD CHANNEL AN9-5

26 SAD CHANNEL AN9-6

27 SAD CHANNEL AN9-7

28 SAD CHANNEL AN10

29 SAD TEST CHANNEL

30 C00L348 (Coolant AID with 348 ohm pull-up)

31 COOL4K (Coolant A/D with 4K ohm pull-up)

32 TESTWORD

Bit 7 = In Factory Test Mode

Bit 6 = NOT USED

Bit 5 =NOT USED

Bit 4 = EPROM CHECKSUM TEST (Code 51), 1= Failed

Bit 3 = NOT USED

Bit 2 = NOT USED

Bit 1 = NOT USED

Bit 0 = NOT USED

33 REFPER - Reference Period (Upper Byte)

34 REFPER - Reference Period (Lower Byte)

35 PP1TIMD - Vehicle Speed Delta (Upper Byte)

36 PPITIMD - Vehicle Speed Delta (Lower Byte)

37 PP2TIMD - 6X Reference Delta (Upper Byte)

38 PP2TIMD - 6x Reference Delta (Lower Byte)

39 PA1CTR - Frequency Mass Air Flow/Vats Pulse Accumulator

40 PA1CTR - Frequency Mass Air Flow/Vats Pulse Accumulator

41 PA2CTR - EST Monitor Integration Period (Upper Byte)

42 PA2CTR - EST Monitor Integration Period (Lower Byte)

43 PA3CTR - ESC Integration Period (Upper Byte)

44 PA3CTR - ESC Integration Period (Lower Byte)

45 PA4CTR - Vehicle Speed Pulse Accumulator (Upper Byte)

46 PA4CTR - Vehicle Speed Pulse Accumulator (Lower Byte)

47 PAlTIMD - Frequency MAF/VATS Delta (Upper Byte)

48 PAlTIMD - Frequency MAF/VATS Delta (Lower Byte)

49 GMP4 Programmable Port I/O Status

50 GMP4 Programmable Port Data Direction (0 = Input, l = Output)

51 FMDBYTE1 (FMD #1)

Bit 7 = A/C

Bit 6 = IDH5

Bit 5 = IDH6

Bit 4 = IDL1

Bit 3 = IDH4

Bit 2 = IDH3

Bit 1 = IDH2

Bit 0 = IDH1

52 FMDBYTE2 (FMD #1)

BIT 7 = IRQ Occurred

BIT 6 = Injector 'A' shorted

BIT 5 = .4V sensed on Driver 'A' (Peak and Hold usage)

BIT 4,3 = 1,1 - TBI or alternating TBI/PFI

1,0 - 4 Cylinder PFI SSDF

0,1 - 6 Cylinder PFI SSOF

0,0 - 8 Cylinder PFI SSDF

BIT 2 = NOT USED

BIT 1 = NOT USED

BIT 0 = NOT USED

53 FMDBYTE1 (FMD #2)

54 FMDBYTE2 (FMD #2)

BIT 7 = IRQ Occurred

BIT 6 = Injector 'B' shorted

BIT 5 = .4V sensed on Driver 'B' (Peak and Hold Usage)

BIT 4,3 = 1,1 - TBI or alternating TBI/PFI

BIT 2 = NOT USED

BIT 1 = NOT USED

BIT 0 = NOT USED

55 SC1 INPUT STATUS

3.2.2 Mode 1 - All Off Mode

When Mode 1 is enabled the following actions take place:

1.Check engine light turned off

2.Serial data driver turned off

3.EST mode disabled

4.Synchronous fuel delivery disabled

5.Asynchronous fuel delivery disabled

6.All discrete outputs de-energized NOTE: An attempt will be made to activate 0F6* and 0F7* through software, but these outputs should be de-energized since the QDMs handling these signals are disabled in backup fuel.

7.All PWM outputs de-energized (0% duty cycle) NOTE: The FAN output will default to ON after a short delay in back-up fuel.

8.IAC output disabled (OFF in backup; on but not moving when not in backup)

9.COP Z not toggled if Mode 1 input conditions remain satisfied (FMD#1 BITS 0 and 1=0)

10.One second ECM turn off delay

It is possible to check backup fuel operation in Mode 1 by applying reference pulses to the ECM

3.2.3 Mode 2 - Input/Output Check Mode

When Mode 2 is enabled, the following actions take place:

1.All A/D inputs read

2.All discrete inputs read

3.All pulse accumulator/pulse period/pulse integrator inputs read

4.PWM outputs activated as follows:

PW1 ( ) 30% duty cycle at a 32 Hz PWM rate.

PW2 ( ) 40% duty cycle at a 32 Hz PWM rate.

PW3 ( ) 50% duty cycle at a 32 Hz PWM rate.

PW4 ( ) 60% duty cycle at a 32 Hz PWM rate.

PWS ( ) 70% duty cycle at a 32 Hz PWM rate.

PW6 ( ) 80% duty cycle at a 32 Hz PWM rate.

5.Discrete outputs energized individually each 100 msec

• • TCC*
  • Check Engine Light
  • 0F5*

6.FAN* and FUEL PUMP cycled as follows:

• • FAN* discrete ON; FUEL PUMP 50% duty cycle at a 32 Hz PWM rate
  • FAN* discrete OFF; FUEL PUMP 50% duty cycle at a 32 Hz PWM rate
  • FAN* 50% duty cycle at a 32 Hz PWM rate; FUEL PUMP discrete ON

7.Vehicle speed buffer option selects (SCI 08,07, and 06) incremented MODULO-8 every 100 msec

8.Step AC motor every 100 msec

9.second ECM turn off Delay

1.If reference period is greater than 10 msec, the following occurs:

• • Synchronous fuel output set at 10 msec, simultaneously delivered
  • No delayed start of injection
  • Spark is set at Reference Period/4 Retard, (45 degrees for 4 cylinder)
  • Dwell time is fixed at 5 msec.

2.If reference period is between 5 and 10 msec, the following occurs:

• • Synchronous fuel output set at 5 msec, alternately delivered
  • No delayed start of injection
  • Spark advance set at 0 deg.
  • Dwell time is fixed at 4 msec.

3.If reference period is less than 5 msec, the following occurs:

• • Synchronous fuel output set at 1 msec, simultaneously delivered
  • msec delayed start of injection
  • Spark is set at Reference Period/4 advance (45 degrees for 4 cylinder)
  • Dwell time is fixed at 3 msec

3.2.4 Mode 3 - Miscellaneous Test Mode

When Mode 3 is enabled the following actions take place:

1.Check engine light turned off

2.EST mode disabled

3.Synchronous fuel delivery disabled

4.All discrete outputs de-energized

5.All PWM outputs de-energized (0% duty cycle) except for asynchronous fuel

6.COP2 toggled

7.Asynchronous fuel output fixed at 3 msec every 6.25 msec

8.Checksum of nonvolatile RAM calculated

9.One second ECM turn off delay

10.IAC outputs on, but not changing state

4.0 Special Consideration

4.1 RAM Usage

When implementing Factory Test Software, RAM locations in all devices containing RAM should be utilized to provide some automatic test of RAM.

4.2 EPROM Checksum

The checksum sent out on serial data (ROMSUM) is the sum of all bytes in the EPROM.

The factory test software also performs a code 51 type test of the EPROM checksum. That is, it compares a calculated checksum against a checksum value located in the EPROM. The result of this test is transmitted by one of the bits in serial data byte named TESTWORD If the code 51 checksum test is bypassed in the EPROM, a test passed indication will be transmitted.