For 1990-2009 cars

### DTC Descriptors

DTC B1000 33: Electronic Control Unit (ECU) Performance Special Memory Failure
DTC B1000 34: Electronic Control Unit (ECU) Performance RAM Integrity
DTC B1000 35: Electronic Control Unit (ECU) Performance ROM Integrity
DTC B1000 36: Electronic Control Unit (ECU) Performance EEPROM Integrity
DTC B1000 39: Electronic Control Unit (ECU) Performance Internal Electronic Failure

### Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle , prior to using this diagnostic procedure.

### Circuit/System Description

The internal fault detection is handled inside the control module. No external circuits are involved.

### Conditions for Running the DTC

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

### Conditions for Setting the DTC

The module has detected an internal malfunction.

### Action Taken When the DTC Sets

The module refuses all additional inputs.

### Conditions for Clearing the DTC

• | A current DTC clears when the malfunction is no longer present.

• | A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

### Diagnostic Aids

• | This DTC may be stored as a history DTC without affecting the operation of the module.

• | If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

• | If this DTC is retrieved as both a current and history DTC, replace the module that the DTC set for.

### Circuit/System Verification

If this DTC is retrieved as a current DTC, replace the module that set the DTC.

### Repair Instructions

Perform the Diagnostic Repair Verification , after completing the repair.

Refer to Control Module References , for the non-communicating module replacement, setup, and programming.