Signal Missing

Connecting The Test Box
- Ignition OFF.
- Connect the test box and check ground terminals.
- Proceed to: Checking Signal Cables For A Short-circuit To Supply Voltage section below.





Checking Signal Cables For A Short-circuit To Supply Voltage
- Ignition OFF.
- Engine control module (ECM) connected.
- Ignition ON.
- Connect an electrician's screwdriver (bulb at least 3W) between test box # 15 and # 39 TC1, # 25 TC2, # 10 TCM.
- The bulb should not light. If the lamp lights there is probably a short-circuit to supply voltage in the circuit.
- Is the bulb out?

Yes:
- Proceed to: Checking Signal Cables For Resistance To Ground section below.

No:
- Proceed to: Checking For A Short-circuit section below.





Checking For A Short-circuit
- Check cables between transmission control module (TCM):

- # 39 and engine control module # B2
- # 25 and engine control module # B3
- # 10 and engine control module # B4
- For a short-circuit to supply voltage.

- Proceed to: Verification section below.





Checking Signal Cables For Resistance To Ground
- Ignition OFF.
- Disconnect the transmission control module and engine control module.
- Connect an ohmmeter between test box # 15 and # 39 TC1, # 25 TC2, # 10 TCM.
- The ohmmeter should read infinite resistance.

If reading is OK:
- Proceed to: Checking Signal Cable TC1/TC2 section below.

If reading is incorrect:
- Proceed to: Checking For A Short-circuit section below.





Checking For A Short-circuit
- Check cables between transmission control module:

- # 39 and engine control module # B2.
- # 25 and engine control module # B3.
- # 10 and engine control module # B4.
- For a short-circuit to ground.

- Proceed to: Verification section below.





Checking Signal Cable TC1/TC2
- Ignition OFF.
- Disconnect test box from automatic transmission control module.
- Connect the test box to the engine control module.
- Connect the transmission control module and engine control module.
- Ignition ON.
- Move gear selector to position P.
- Connect a voltmeter between ground and: # 2 (# B2) TC1 # 3 (# B3) TC2.
- Use the ACTIVATION function to activate TC/TC2.
- The voltmeter reading should oscillate between: Approx. 0 Volts and 0-2 below U bat.
- Oscillation is rapid, approx. 1 second.
- Does the reading oscillate?

Yes:
- Proceed to: Checking Transmission Control Module Signal Cable section below.

No:
- Proceed to: Checking For An Open-circuit section below.





Checking For An Open-circuit
- Check cables between transmission control module:

- # 39 and engine control module # B2.
- # 25 and engine control module # B3.
- for an open-circuit.

- Proceed to: Verification section below.





Checking Transmission Control Module Signal Cable
- Ignition ON.
- Move gear selector to position P.
- Activate torque limiting TC1/TC2. Read off transmission control module torque limiting acknowledgement status. The status should alternate between NO/YES.
- Does the status alternate between OFF/ON?

Yes:
- Proceed to: Intermittent Fault section below.

No:
- Proceed to: Checking For An Open-circuit section below.





Checking For An Open-circuit
- Check cable between transmission control module # 10 and engine control module # B4 for an open-circuit.
- Proceed to: Verification section below.





Verification
After repairs have been completed they must be verified as follows to ensure that the fault has been eliminated:

- Ignition OFF.
- Reconnect connectors, reinstall components etc.
- Test box connected to engine control module.
- Control modules connected.
- Ignition ON.
- Move gear selector to position P.

- Connect a voltmeter between ground and test box terminals:

- # 2 (# B2) TC1.
- # 3 (# B3) TC2.

- Activate torque limiting TC1/TC2.
- The voltmeter reading should rapidly oscillate down to approx. 0 Volts when the signal is activated (this oscillation is rapid, approx. 1 second).
- Does the signal oscillate?

Yes:
- Continue with Verification testing below.

No:
- Proceed to: Fault-tracing Information section below.





- Ignition ON.
- Move gear selector to position P.
- Activate torque limiting TC1/TC2. Read off transmission control module torque limiting status. The status should alternate between NO/YES.
- Does the status alternate between OFF/ON?

Yes:
- Fault corrected.

No:
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
The verification result shows that the fault persists.

- Do you want to exit fault-tracing?

Yes:
- Fault not corrected.

No:
- SB2





Intermittent Fault
- Ignition OFF.
- Check transmission control module and engine control module connectors for contact resistance and oxidation.
- Check the cable between transmission control module # 39 and engine control module # B2 for an intermittent open-circuit, intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- Check the cable between transmission control module # B25 and engine control module # B3 for an intermittent open-circuit, intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- Check the cable between transmission control module # 10 and engine control module # B4 for an intermittent open-circuit, intermittent short-circuit to ground and an intermittent short-circuit to supply voltage.
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
For intermittent faults fault-tracing is not followed by a verification because the fault is not present at this moment.

- Do you want to repeat fault-tracing?

Yes:
- Proceed to: Checking Signal Cables For A Short-circuit To Supply Voltage section above

No:
- Operation done.