Difference between revisions of "Holden:Instrument Cluster"

Latest revision as of 04:49, 10 May 2021

Overview

The instrument cluster is a self-contained module in the dash featuring the speedometer, tachometer, fuel gauge, temperature gauge and usually a trip computer retaining information such as the odometer.

VT/VX/VY/VZ Commodores

Unlock Procedure

Before any configuration data can be read or written, the cluster must be in an "unlocked" state. This is achieved using a challenge-response authentication mechanism (also known as a seed/key pair). A seed can be requested from the cluster by issuing a Mode 11 request, followed by table number 00. The cluster will respond with Mode 11 and two bytes that form the seed. The key value is calculated and sent as a write to table 01 in Mode 11. For details on calculating key values, see GM Seed/Key. The tables below illustrate the unlocking procedure.

Seed request

Length (bytes)	Field	Value
1	ID	`F2`
1	Length	`57`
1	Mode	`11`
1	Table	`00`
1	Checksum	`A6`

Seed response

Length (bytes)	Field	Value	Notes
1	ID	`F2`
1	Length	`59`
1	Mode	`11`
2	Seed	S	16-bit Seed Value
1	Checksum	c

Key transmission

Length (bytes)	Field	Value	Notes
1	ID	`F2`
1	Length	`59`
1	Mode	`11`
1	Table	`01`
2	Key	K	16-bit Key Value
1	Checksum	c

Key response

Length (bytes)	Field	Value	Notes
1	ID	`F2`
1	Length	`58`
1	Mode	`11`
2	Status		Equals key K on successful unlock, `FFFF` on failure.
1	Checksum	`F8`

Configuration Tables

Table	Length	Type	Description
`01`	`2`	`u16`	Speedometer Pulses
`50`	`1`	Boolean	Police Mode
`55`	`4`	`u32`	Odometer reading at the time of programming (set by scan tool)
`66`	`1`	`u8`	SRS Configuration (see SRS Configuration section)
`67`	`1`	Boolean	Show Distance To Go
`69`	`1`	Boolean	Show radio status
`6D`	`1`	Boolean	Stopwatch
`7E`	`1`	Boolean	Automatic Transmission

SRS Configuration

The instrument cluster's SRS configuration must match the configuration of the SRS module installed in the vehicle. A mismatched configuration will set a DTC in the SRS module itself (and trigger a warning on the cluster). The SRS DTC will need to be cleared separately after the cluster is properly configured. The table below lists the various SRS configurations, and their corresponding values.

Value	Configuration
`00`	None
`01`	2 Loop
`02`	3 Loop
`03`	4 Loop
`04`	6 Loop

@@ Line 83: / Line 83: @@
 |-
 | style="text-align:center;" | <code>50</code> || style="text-align:center;" | <code>1</code> || style="text-align:center;" | Boolean || Police Mode
+|-
+| style="text-align:center;" | <code>55</code> || style="text-align:center;" | <code>4</code> || style="text-align:center;" | <code>u32</code> || Odometer reading at the time of programming (set by scan tool)
+|-
+| style="text-align:center;" | <code>66</code> || style="text-align:center;" | <code>1</code> || style="text-align:center;" | <code>u8</code> || SRS Configuration (see [[#SRS Configuration|SRS Configuration]] section)
 |-
 | style="text-align:center;" | <code>67</code> || style="text-align:center;" | <code>1</code> || style="text-align:center;" | Boolean || Show Distance To Go
@@ Line 91: / Line 95: @@
 |-
 | style="text-align:center;" | <code>7E</code> || style="text-align:center;" | <code>1</code> || style="text-align:center;" | Boolean || Automatic Transmission
+|}
+==== SRS Configuration ====
+The instrument cluster's SRS configuration must match the configuration of the SRS module installed in the vehicle. A mismatched configuration will set a DTC in the SRS module itself (and trigger a warning on the cluster). The SRS DTC will need to be cleared separately after the cluster is properly configured. The table below lists the various SRS configurations, and their corresponding values.
+{|class="wikitable"
+! Value !! Configuration
+|-
+| style="text-align:center;" | <code>00</code> || None
+|-
+| style="text-align:center;" | <code>01</code> || 2 Loop
+|-
+| style="text-align:center;" | <code>02</code> || 3 Loop
+|-
+| style="text-align:center;" | <code>03</code> || 4 Loop
+|-
+| style="text-align:center;" | <code>04</code> || 6 Loop
 |}