Speedometer issues
Thread Starter
3rd Gear
Joined: Aug 2020
Posts: 3
Likes: 0
Speedometer issues
I have a 2001 C5. The speedo will not register and the HUD shows zeo. The cruise works and DIC displays cruise speed. I had the speedo cluster out to work on HVAC actuator and this started after. I have checked the plug to be sure it is installed all the way. I have also cleaned the grounds in the engine bay. When I start the car the needle moves thru its range so the speedo motor is working. Any ideas?
Speedy
Joined: Mar 2007
Posts: 6,107
Likes: 929
From: Tn
2024 C8 of the Year Finalist - Modified
I have a 2001 C5. The speedo will not register and the HUD shows zeo. The cruise works and DIC displays cruise speed. I had the speedo cluster out to work on HVAC actuator and this started after. I have checked the plug to be sure it is installed all the way. I have also cleaned the grounds in the engine bay. When I start the car the needle moves thru its range so the speedo motor is working. Any ideas?
I think the transmission has one too
Melting Slicks
Joined: Jul 2004
Posts: 3,294
Likes: 480
From: Brea CA
The DIC display gets the speed for cruise control from the serial data bus. The speedometer/HUD get this info from a discrete wire that comes from the PCM to the IPC. Pin A7 on the IPC connector has the VSS signal (Speedometer). Check for damage to that wire from the connector down the harness. In the 2002 service manual this is a Green wire with a White tracer.
With the description of the work you did before this quit working I would say the break in this wire is within 12 inches of the IPC connector. It is possible that the wire is broken with in the connector.
Gary
With the description of the work you did before this quit working I would say the break in this wire is within 12 inches of the IPC connector. It is possible that the wire is broken with in the connector.
Gary
Thread Starter
3rd Gear
Joined: Aug 2020
Posts: 3
Likes: 0
So I ohmed out the wire could not find any breaks. I was pulling the speedometer apart to examine the circuit board and noticed the plugin on top of the speedo for the HUD had 1 prong pushed over against the other on the far right. I separated them plugged in the speedometer and it worked., Reassembled everything and now speedometer and HUD work fine. I must have pushed the prong when I plugged in the HUD the first time I reassembled after working on the AC actuator.
