Bosch Tech 2 User Manual

Troubleshooting
Te c h  2Page 6-11
F2: Automated VCI Test 
This test works the same as the Automated Main PCB and VCI test, except the PCB portion of the test is not 
included (Figure 6-10). 
FIGURE 6-10. Automated VCI Test Selected on Tech 2 Self Test Main Menu 

Troubleshooting
Page 6-12Te c h  2
F3: Selectable Main PCB Test 
Select F3: Selectable Main PCB (Figure 6-11) after a fail message has been displayed during the 
Automated Main PCB and VCI or Automated Main PCB tests. When you select F3: Selectable Main PCB, 
a screen like the one shown in Figure 6-12 is displayed. You may then select individual tests for failed 
components. For specific information on failed components, refer to the Main Printed Circuit Board (PCB) 
Diagnostic Chart (Ta b l e 6 - 1 ,...

Troubleshooting
Te c h  2Page 6-13
F4: Selectable VCI Test 
Select F4: Selectable VCI (Figure 6-13) after a fail message displays during the Automated Main PCB and 
VCI or Automated VCI tests. When you select F4: Selectable VCI, a screen like the one shown in Figure 6-
14 is displayed. You may select individual tests for failed components from this screen. If you select More 
Tests, a screen like the one shown in Figure 6-15 is displayed. If you then select Previous Menu, the screen 
shown in Figure 6-14...

Troubleshooting
Page 6-14Te c h  2
 
FIGURE 6-15. Second Selectable VCI Self Test Screen 

Troubleshooting
Te c h  2Page 6-15
F5: Power On Self Test Results 
Select F5: Power On Self Test Results (Figure 6-16) after a fail message displays during the Power On 
Self Test (POST). Specific information on the failure displays on the screen. Select F0, F1, F2, F3, or F4 to 
further isolate the specific fault. 
FIGURE 6-16. Power On Self Test Results Selected on Tech 2 Self Test Main Menu 

Troubleshooting
Page 6-16Te c h  2
NO POWER TO TECH 2 
TROUBLESHOOTING TABLES 
Use the following tables to diagnose, isolate, and correct power source problems that may cause a No Power 
condition to your Tech 2 scan tool. 
To help determine the power supply source, see Chapter 4. 
Power Source: DLC Cable
Ste pActionYe sNo
1 Does vehicle support power through 
DLC cable connection exclusively? (If 
you are not sure, consult your service 
manual.) Go to Step 2. Use alternate power.
2 • Using a digital...

Troubleshooting
Te c h  2Page 6-17
Power Source: Cigarette Lighter Power Cable
StepActionYe sNo
1 • Unplug cigarette lighter power cable 
from DLC cable. 
• Using a digital multi-meter (DMM), 
verify voltage output at cigarette 
lighter power cable power jack. 
Do you have battery voltage output? Go to Step 3.  Go to Step 2. 
2 • Check fuse in cigarette lighter power 
cable (refer to Figure 6-17). 
Does fuse need replacing? Replace fuse.  Go to step 3.
3 • Remove DLC cable from Tech 2. 
• Plug in...

Troubleshooting
Page 6-18Te c h  2
Power Source: Battery Power Cable
Ste pActionYe sNo
1 • Unplug battery power cable power 
jack from DLC cable. 
• Using a digital multi-meter (DMM), 
verify voltage output at battery power 
cable power jack. 
Do you have battery voltage output?Go to Step 3.  Go to Step 2. 
2 • Check fuse(s) in battery power cable 
(refer to Figure 6-18). 
Does fuse(s) need replacing? Replace fuse(s).  Go to Step 3.
3 • Remove DLC cable from Tech 2. 
• Plug in battery power cable power...

Troubleshooting
Te c h  2Page 6-19
CIGARETTE LIGHTER POWER CABLE 
3-AMP FUSE REPLACEMENT 
A three-amp removable fuse is located in the cigarette lighter power cable (P/N 02002954) connector. 
When required, check or replace the fuse by performing the following steps: 
1. Ensure the cigarette lighter power cable is not connected to the vehicle or Tech 2.
2. Unscrew the fuse retainer cap and remove the 3-amp fuse. 
3. Inspect the fuse for damage and replace it with an identical 3-amp fuse if required. 
4....

Troubleshooting
Page 6-20Te c h  2
BATTERY POWER CABLE 3-AMP FUSE 
REPLACEMENT 
Two three-amp fuses are located in the battery power cable (P/N 02002956) three-amp fuse box. 
When required, check or replace the fuse(s) by following the steps below. 
 
1. Ensure the battery power cable is not connected to the vehicle battery or Tech 2. 
2. Use a standard fuse puller to remove the fuse(s) from the fuse box. 
3. Inspect the fuse(s) for damage and replace with identical 3-amp fuse(s) if required. 
4. Verify...