For 1990-2009 cars

### Diagnostic Instructions

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

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provide an overview of each diagnostic category.

### DTC Descriptors

DTC P167D: Ignition Control (IC) Performance

### Circuit/System Description

The ignition system on this engine uses individual ignition coils and ignition control (IC) circuits for each cylinder. Ignition voltage is supplied to each bank of ignition coils. Each ignition coil, with its control circuit is connected to a separate ignition driver module within the engine control module (ECM). The ECM detects faults and controls the ignition system operation using this separate ignition driver module via an SPI bus circuit. The ignition driver module controls each coil using the IC circuits. The ignition driver module commands the IC circuit low when a spark event is requested. The ECM monitors the configuration of the ignition driver module and it ability to communicate with the ECM to determine if a fault exists.

### Conditions for Running the DTC

• | The engine is operating.

• | The igniting voltage is between 9-18 volts.

• | The engine speed is less than 6000 RPM.

• | DTC P167D runs continuously once the conditions above are met.

### Conditions for Setting the DTC

The ECM detects a condition with the integrated circuits of the ignition driver module for greater than 4 seconds or for a cumulative of 50 seconds.

### Action Taken When the DTC Sets

DTC P167D is a Type B DTC.

### Conditions for Clearing the DTC

DTC P167D is a Type B DTC.

### Diagnostic Aids

If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### Description and Operation

Electronic Ignition (EI) System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Idle the engine, view the DTC information with a scan tool. DTC P167D should not set.

⇒ | If DTC P167D failed this ignition, replace the ECM.

2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for engine control module replacement, setup, and programming