The powertrain control module (PCM) receives two ignition inputs from the ignition switch: IGN 0 and IGN 1. The PCM receives the Crank Request input with the ignition switch in the START position. The PCM uses a class 2 ignition mode message, and the voltage input from two separate systems to test the Crank Request circuit. If the PCM detects an improper input, DTC P0512 will set.
No Class 2 serial data circuit problem.
The PCM detects an improper Crank Request input.
• | The PCM will not illuminate the malfunction indicator lamp (MIL). |
• | The PCM will store conditions which were present when the DTC set as Fail Records information only. |
• | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
• | The DTC can be cleared by using the scan tool Clear DTC Information function. |
If the condition is intermittent, refer to Intermittent Conditions in Symptoms.
Depending upon the circuit condition, symptoms of P0512 may be that the engine does not crank, or the engine cranks in the RUN position.
Step | Action | Value(s) | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | |||||
2 |
Important: If the vehicle runs with the ignition turned OFF, repair the PCM Ignition 1 circuit for a short to B+. Is DTC P1634 also set? | -- | Go to Step 6 | Go to Step 3 | ||||
3 | Does the engine crank with the ignition switch in the Run position? | -- | Go to Step 4 | Go to Diagnostic Aids | ||||
4 |
Is the test lamp ON? | -- | Go to Step 5 | Go to Step 12 | ||||
5 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 | ||||
6 |
Is the test lamp ON? | -- | Go to Step 7 | Go to Step 8 | ||||
7 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | ||||
8 | Inspect the Batt 2 fuse. Is the fuse open? | -- | Go to Step 9 | Go to Step 10 | ||||
9 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | ||||
10 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 | ||||
11 | Replace the ignition switch. Refer to Steering Column Lock and Ignition Switch Cylinder Replacement - On Vehicle in Steering Wheel and Column - Tilt. Is the action complete? | -- | Go to Step 13 | -- | ||||
12 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | Go to Step 13 | -- | ||||
13 |
Does the scan tool indicate that DTC P0512 passed? | -- | System OK | Go to Step 2 |