Circuit Description
The controller area network (CAN) serial data bus is used by the engine control module (ECM) and automatic transmission control module (TCM) to share information. An example of information shared is engine speed, engine coolant temperature, manifold absolute pressure (MAP), throttle position and vehicle speed.
If the ECM does not receive a message from the TCM, this DTC sets.
Conditions for Setting the DTC
| • | The ignition switch is turned to ON. |
| • | Ignition voltage is greater than 11 volts. |
| • | The engine is running more than 2 seconds. |
| • | The device control is not active. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | The MIL turn OFF after 4 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||||
2 |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Intermittent Conditions | ||||||
3 | Attempt to establish communication with the TCM with a scan tool. Does the scan tool communicate? | -- | Go to Step 4 | Go to Scan Tool Does Not Communicate with Component in Data Link Communications | ||||||
4 |
Is the voltage within the specified range? | 1.5-3.4 V | Go to Step 5 | Go to Step 6 | ||||||
5 | Test the CAN serial data high and low circuits for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 | ||||||
6 | Test for shorted terminals and poor connections at the transmission control module (TCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 | ||||||
7 | Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 | ||||||
8 | Replace the transmission control module (TCM). Refer to Transmission Control Module Replacement in Automatic Transmission - Aisin (81-40LE). Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||
9 | Replace the engine control module (ECM). Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||
10 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 11 | ||||||
11 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |
