Code 52

Code 52 is a diagnostic trouble code related to the ECM CALPAK on the Pontiac Fiero.

Code 52 indicates that the ECM has detected a problem with the CALPAK, CALPAK installation, CALPAK connection, or related ECM backup-calibration function.

Overview

The CALPAK is a calibration package used by the ECM. It provides backup calibration information that allows the ECM to operate in a limited mode if certain ECM or PROM functions fail.

Code 52 is set when the ECM detects a CALPAK-related problem.

Flash pattern

Code 52 is displayed as:

• Five flashes
• Pause
• Two flashes

This represents code 52.

Animated flash pattern:

Meaning

Code 52 usually indicates a CALPAK error.

Possible causes include:

• CALPAK not seated correctly
• Wrong CALPAK installed
• Damaged CALPAK
• Corroded CALPAK contacts
• ECM internal problem
• Poor ECM connector contact
• Previous ECM modification
• Electrical damage to the ECM or CALPAK

Symptoms

Possible symptoms may include:

• Check engine light
• No-start condition
• Poor drivability
• Poor idle
• Engine runs poorly
• Incorrect fuel or spark behavior
• Backup or limp-home behavior, depending on the failure
• Little or no obvious drivability problem in some cases

Diagnosis

Basic diagnostic checks include:

1. Confirm that Code 52 is present.
2. Check whether the ECM has been replaced or modified.
3. Check whether the CALPAK has been changed.
4. Inspect the ECM connectors.
5. Inspect the CALPAK seating if the ECM is opened.
6. Check for corrosion or damaged terminals.
7. Verify that the correct CALPAK is installed.
8. Check for other stored trouble codes.
9. Consider ECM failure if the CALPAK and connections appear correct.

CALPAK

The CALPAK is located inside the ECM and should be handled carefully. Bent pins, corrosion, static damage, incorrect installation, or using the wrong part can cause ECM-related problems.

Related topics:

• CALPAK
• ECM
• ECM replacement
• Engine management

PROM and CALPAK relationship

Code 52 is related to the CALPAK, while Code 51 is related to the PROM. Both codes involve calibration or memory components inside the ECM.

Related topics:

• PROM
• CALPAK
• Code 51
• ECM

Notes

Code 52 should be treated carefully because it relates to ECM calibration and backup operation. Do not replace parts randomly without checking whether the ECM and CALPAK are correct for the vehicle.

If the ECM has been opened recently, verify that the CALPAK is installed correctly and fully seated.

See also

• Diagnostic trouble codes
• ALDL diagnostics
• ECM
• CALPAK
• PROM
• Code 51
• Code 55
• Electrical system