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Ken
Ken, ASE Certified Technician
Category: Chevy
Satisfied Customers: 754
Experience:  GM Certified Technician, 25 Years Automotive Experience
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2000 chevy s10: The speedometer and odometer..diagnostic..voltage

Resolved Question:

The speedometer and odometer on my 2000 chevy s10 with 2.2L engine has stopped working. When connecting to the diagnostic port the computer knows how fast the truck is going but 99% of the time the speedometer and odometer do nothing, all other guages in the instrument cluster work fine. I have tried to trace the wire using a wiring diagram but I haven't been able to find a good pin layout for where the wire should be hooked up behind the glove box and what the voltage/ohms should be when testing the wire. Any help would be greatly appreciated.
Submitted: 7 years ago.
Category: Chevy
Expert:  Ken replied 7 years ago.

Hi and thanks for your question! Your next step will be to have the cluster tested. You will need to find a shop that has a scan tool that can do a sweep test on the cluster.

99% of the time I find a bad gauge. Then you will need to send it in for repair.

Thank You KenObject Number: 604886  Size: LF

Customer: replied 7 years ago.
I will get the instrument cluster checked as soon as I can but I was wondering if you could tell me which pin(s) in the connector behind the dash supplies the signal to the speedometer and what the voltage/amperage/ohms should be. Also can I check this on the connector for the radio where it has the speed controlled volume option to make sure that I am not getting a signal at one point and not the other.
Expert:  Ken replied 7 years ago.

 

Value(s)

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

--

Go to Step 3

Go to Diagnostic System Check - Instrument Cluster

2

    Important: If the instrument cluster is completely inoperative, .

  1. Install a scan tool.
  2. Raise the vehicles drive wheels. Start the engine.
  3. Place the transmission into drive for automatic transmission and third gear for manual transmission.
  4. Compare the displayed vehicle speed on the Instrument Cluster with the monitored speed on the scan tool.

Does the vehicles speedometer and the scan tool both display 0 km/h (0 mph)?

--

Go to Step 4

Go to Step 3

3

Does the vehicles speedometer approximately agree with the scan tool display?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the in line connector C101.
  3. Turn ON the ignition.
  4. Test the vehicle speed output (4K) circuit voltage from the in line connector C101 (female side of connector) to a good ground using the DMM J 39200 . .

Does the DMM display a voltage greater than the specified value?

9.5V

Go to Step 8

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Remove the instrument cluster. Test the continuity from the vehicle speed sensor signal (4K) circuit at the instrument cluster electrical connector to the in line connector C101. Does the DMM display continuity?

--

Go to Step 6

Go to Step 10

6

Test the continuity from the vehicle speed sensor signal (4K) circuit to a good ground. Does the DMM display continuity?

--

Go to Step 11

Go to Step 7

7

Test the instrument cluster harness connector for a poor connection to the instrument cluster. Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

8

  1. Turn OFF the ignition.
  2. Disconnect the PCM/VCM harness connector which contains the vehicle speed sensor signal circuit. Test the continuity of the vehicle speed sensor signal (4K) circuit from the PCM/VCM harness connector to the in line connector C101 using the DMM J 39200 . .

Does the DMM display continuity?

--

Go to Step 9

Go to Step 12

9

Test the continuity of the vehicle speed sensor signal (4K) circuit from the PCM/VCM harness connector to a good ground using the DMm .

Does the DMM display continuity?

--

Go to Step 13

Go to Step 14

10

Repair the open vehicle speed sensor signal (4K) circuit from the instrument cluster electrical connector to the in line connector C101. Did you complete the repair?

--

Go to Step 17

--

11

Important: If you cannot locate a grounded circuit, disconnect each component (one at a time) and see if the grounded condition is caused by a component on the vehicle speed sensor signal (4K) circuit. Repair the grounded vehicle speed sensor signal (4K) circuit from the instrument cluster connector to the in line connector C101. Did you complete the repair?

--

Go to Step 17

--

12

Repair the open vehicle speed output (4K) circuit from the PCM/VCM harness connector to the in line connector C101. ?

--

Go to Step 17

--

13

Repair the grounded vehicle speed output (4K) circuit from the PCM/VCM harness connector to the in line connector C101. Did you complete the repair?

--

Go to Step 17

--

14

Test the PCM/VCM harness connector for poor connections. Did you find and correct the condition?

--

Go to Step 17

Go to Step 15

15

Important: Program the replacement PCM/VCM. Controls - 2.2L Controls - 4.3L.

Replace the PCM/VCM.

Did you complete the replacement?

--

Go to Step 17

--

16

Replace the instrument cluster. .

Did you complete the replacement?

--

Go to Step 17

--

17

Operate the system in order to verify the repair.

Did you find and correct the condition?

--

System OK

Go to Step 4

Expert:  Ken replied 7 years ago.
Object Number: 548112  Size: FS
Expert:  Ken replied 7 years ago.

Instrument Cluster Connector


Object Number: 191573  Size: CF

Connector Part Information

12110088
24-Way F Micro-Pack 100 Series (GRY)

Pin

Wire Color

Circuit No.

Function

A1

--

--

Not Used

A2

TAN/WHT

331

Oil Sender Sensor Signal

A3

WHT

121

Tachometer Signal

A4

DK GRN

389

Vehicle Speed Signal Input - 4,000 Pulses Per Mile

A5

BRN

41

Fuse Output - Ignition 3

A6

GRY

1036

Class 2 Serial Data

A7

PNK

39

Fuse Output - Ignition 1

A8

PNK

1020

Fuse Output - Ignition 0

A9

BLK/WHT

451

Ground for the IPC

A10

ORN

340

Fuse Output - Battery

A11

BRN/WHT

419

Check Engine Indicator Lamp Output

A12

ORN/BLK

1786

Transmission Park/Neutral Signal

B1

LT BLU/WHT

1414

Left Turn Signal Switch Input

B2

GRY

1220

Fuse Output - Instrument Panel Lamps

B3

BLK

1050

Ground

B4-B10

--

--

Not Used

B11

DK BLU/WHT

1415

Right Turn Signal Switch Input

B12

--

--

Not Used

Expert:  Ken replied 7 years ago.
The speedo gets it signal on the class 2 communication wire. The modules decodes the signals. If you had a problem, all kinds of things will not work on the cluster and you will have fault codes stored in all the computers. Thank You Ken
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