Circuit Description
The ENG IGN mini fuse supplies an ignition voltage directly to the 1 to 4 Upshift Lamp. The PCM controls the lamp by grounding the control circuit via an internal switch called a driver. The driver supplies the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status changes causing the DTC to set.
Conditions for Running the DTC
| • | The engine speed is greater than 600 RPM. |
| • | Ignition voltage greater than 6.0 volts but less than 16 volts. |
Conditions for Setting the DTC
| • | The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match. |
| • | All conditions exist for a minimum of 10 seconds. |
Action Taken When the DTC Sets
| • | The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL/DTC. |
Diagnostic Aids
Important: Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM\TAC modules.
Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data determines how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.
For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Important: If the I/P is completely inoperative, refer to Body and Accessories for further diagnosis.
Listen for an audible click when the solenoid operates. Command both the ON and the OFF states. Repeat the commands as necessary.
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If you do not find any trouble in the control circuit or the connection at the PCM, the PCM may be faulty. However, this is an extremely unlikely failure.
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This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only display when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||
Does the shift lamp turn ON and OFF when commanded? | -- | Go to Diagnostic Aids | ||||||||
3 |
Is the shift lamp OFF? | -- | ||||||||
4 | Probe the shift lamp control circuit in the PCM harness connector with a fused jumper wire connected to ground. Is the shift lamp ON? | -- | ||||||||
5 | Repair the short to ground in the shift lamp control circuit . Refer to Body and Accessories/Wiring Systems. Is the repair complete? | -- | -- | |||||||
6 | Check the connections at the PCM. Did you find and correct the condition? | -- | ||||||||
7 | Check for the following conditions:
Refer to Body and Accessories/Wiring Systems. Is the repair complete? | -- | -- | |||||||
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Important:: Program the replacement PCM. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement . Replace the PCM. Is the action complete? | -- | -- | ||||||||
Does the scan tool indicate that this test failed? | -- | |||||||||
10 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
