Gauge Control Module (Speedo) Input Test

NOTE: Before testing, do the gauge control module self-diagnostic function and make sure the B-CAN communication line is OK.

1.Turn the ignition switch OFF.

2.Remove the gauge control module (speedo) and disconnect the 12P connector from it.

 

3.Inspect the connector and socket terminals to be sure they are all making good contact.

  • If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
  • If the terminals are OK, go to 4.

4.With the connector still disconnected, make these input tests at the connector.

  • If any test indicates a problem, find and correct the cause, then recheck the system.
  • If all the input tests prove OK, go to 5.

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained 
11 BLU Ignition switch ON, turn signal switch in LEFT Check for voltage to ground:
There should be battery voltage when the lights are flashing. 
  • Faulty MICU
  • Faulty combination light switch
  • An open in the wire
 
12 GRN Ignition switch ON, turn signal switch in RIGHT Check for voltage to ground:
There should be battery voltage when the lights are flashing. 
  • Faulty MICU
  • Faulty combination light switch
  • An open in the wire
 
LT GRN Under all conditions (disconnect the gauge control module (tach) 36P connector) Check for continuity between the No. 7 terminal and gauge control module (tach) 36P connector No. 20 terminal:
There should be continuity. 
An open in the wire 
Check for continuity between the No. 7 terminal and body ground:
There should be no continuity. 
A short ground in the wire 

5.Reconnect the connector to the gauge control module (speedo), and make these inputs test at the connector.

  • If any test indicates a problem, find and correct the cause, then recheck the system.
  • If the input test proves OK, the gauge control module (speedo) must be faulty; replace it.

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained 
BLK Under all conditions Check for voltage to ground:
There should be less than 0.5 V. 
  • Poor ground (G504)
  • An open in the wire
 
WHT Under all conditions Check for voltage to ground:
There should be battery voltage. 
  • Blown No. 23 (10 A) fuse in the under-hood fuse/relay box
  • An open in the wire
 
BRN Ignition switch ON (II) Check for voltage to ground:
There should be battery voltage. 
  • Blown No. 10 (7.5 A) fuse in the under-dash fuse/relay box
  • An open in the wire