Engine Controls - Tests W/codes: Diagnosis Jaguar XJS Series 3

DTC 12: Mass Airflow Sensor

1. Ensure engine is not misfiring. If necessary, check crankshaft position sensor, timing ring, and sensor air gap. Check voltage at mass airflow sensor pin No. 1 or 2 (zero volts) and pin No. 5 (12 volts).
2. Check mass airflow sensor output voltage. For Specifications, see the «ADJUSTMENTS»(ref-17102) article in this section. Ensure mass airflow sensor has not been subjected to water. If necessary, dry out air intake system. Check intake duct for blockage. Repair or replace as necessary.

DTC 14: Engine Coolant Temperature Sensor

Information is not available from manufacturer.

DTC 16: Air Temperature Sensor

Information is not available from manufacturer.

DTC 17: Throttle Position Sensor

Information is not available from manufacturer.

DTC 18: Throttle Position Sensor

Information is not available from manufacturer.

DTC 22: Heated Oxygen Sensor/Fuel Pump Relay

1. Ensure pin 85 at fuel pump/oxygen sensor heater relay is grounded while engine is cranking. If not grounded, go to next step. If grounded, go to step 3).
2. Check that Engine Control Module (ECM) terminal No. 7 (Pink/Brown wire) is grounded while engine is cranking. If not grounded, replace ECM. If grounded, check for open wiring harness between ECM and fuel pump/oxygen sensor heater relay.
3. With ignition on, check for 12 volts at pin No. 86 of fuel pump/oxygen sensor heater relay. If voltage is not present, check for an open circuit in White/Brown wire back to main relay. If voltage is present, check or replace faulty fuel pump/oxygen sensor heater relay.

DTC 23: Fuel Control, Running Rich

1. If EVAP canister purge control valve has an electrical signal, go to DTC 89. If no electrical signal is present, check fuel pressure at idle. Fuel pressure should be 36.3 psi (2.5 kg/cm 2 ) with vacuum hose connected to fuel pressure regulator, or 43.5 (3.0 kg/cm 2 ) with vacuum hose disconnected.
2. If fuel pressure is incorrect, check fuel pressure return line for blockage. Check vacuum signal if fuel pressure is high with vacuum hose connected. If necessary, replace fuel pressure regulator.
3. If fuel pressure is okay, check for leaking fuel injector and DTC 34. Check mass airflow sensor. Repair or replace as necessary.

DTC 24: Ignition Amplifier

Check continuity of ignition amplifier wiring harness. Check for faulty ignition amplifier. Repair or replace as necessary.

DTC 26: Air Leak, Running Lean

1. Check if air pump is running when engine is hot. Air pump should work for a short period after each hot start or work for several minutes following a cold start. If air injection system is not functioning properly, check air injection system.
2. If air injection system is functioning properly, check exhaust manifold or oxygen sensor for leakage. Check that fuel pressure is correct when engine is running under load. Repair or replace as necessary.
3. Check for vacuum leaks to A/C system and EGR valve. Check for leaks at EGR valve transfer pipe and intake manifold. Check air induction system for leaks at elbow and hoses. Check PCV and EVAP systems for leaks, including dipstick. Repair or replace as necessary.

DTC 29: Electronic Control Module

Replace faulty Electronic Control Module (ECM).

DTC 33: Leaking Fuel Injector

Information is not available from manufacturer.

DTC 34: Leaking Fuel Injector

Information is not available from manufacturer.

DTC 37: EGR Solenoid Valve

1. Ensure EGR control solenoid is properly connected. Check continuity of wiring harness between ECM and EGR control solenoid. Repair or replace as necessary.
2. Ensure EGR control solenoid resistance is approximately 40 ohms. Apply parking brake and service brakes. Ensure ECM is grounding EGR control solenoid Green/Red wire with engine at 1200 RPM (engine at normal operating temperature). Replace ECM if it is not grounding EGR control solenoid.

DTC 39: EGR Function

1. With engine at normal operating temperature and transmission in Neutral, lift EGR valve diaphragm. Engine should run rough and RPM should decrease. If engine does not run rough, check EGR transfer pipe, intake manifold, and EGR valve for blockage.
2. If engine runs rough, apply parking brake and service brakes. With engine hot, ensure vacuum signal to EGR valve is present at 1200 RPM. If vacuum signal is not present, ensure ECM is grounding EGR control solenoid Green/Red wire or check vacuum hose routing.
3. If vacuum signal is present, ensure EGR valve functions properly when vacuum is applied. Replace EGR valve if necessary. Ensure ECM is receiving EGR temperature sensor signal. See the appropriate «SENSOR RANGE CHARTS»(ref-17073) article in this section. Check continuity of wiring harness between ECM and EGR temperature sensor. Repair or replace as necessary.

DTC 44: Heated Oxygen Sensor

1. Ensure heated oxygen sensor is properly connected. Check continuity of wiring harness between ECM, fuel pump/oxygen sensor heater relay, and heated oxygen sensor.
2. Ensure heated oxygen sensor is receiving 12 volts from fuel pump/oxygen sensor heater relay. Check heated oxygen sensor ground circuit. Ensure tip of heated oxygen sensor is not damaged. Repair or replace as necessary.

DTC 46 & 47: Idle Air Control Valve

Check ECM main relay power input, ignition switch power input, and ECM battery power input circuits to ECM small signal ground circuit. See the PIN VOLTAGE CHART S article in this section. See below. Voltage input readings should be within 200 millivolts of each other. If necessary, repair wiring harness. Check for faulty ECM.

1. For XJ6: «PIN VOLTAGE CHARTS»(ref-17074)
2. For XJS: «PIN VOLTAGE CHARTS»(ref-17108)

DTC 48: Idle Air Control Valve Position

Ensure idle air control valve hoses are not blocked, pinched, or restricted. Ensure idle air control valve is not stuck. Repair or replace as necessary. Reset base idle speed. See ADJUSTMENTS article in this section.

DTC 66: Air Injection Pump Relay

1. If air injection pump is operating continuously, air injection pump relay output circuit (Green/Black wire) may be grounded. Check wiring harness for short circuit to ground. If necessary, repair wiring harness or replace faulty air injection pump relay.
2. If air injection pump does not operate continuously, ensure air pump works for a short period after each hot start or works for several minutes following a cold start. Check air injection pump relay output circuit at pump relay. See the appropriate PIN VOLTAGE CHART S article in this section. See below. If necessary, repair wiring harness or replace faulty air injection pump relay. Check for faulty ECM. For XJ6: «PIN VOLTAGE CHARTS»(ref-17074) For XJS: «PIN VOLTAGE CHARTS»(ref-17108)

DTC 68: Speed Sensor

Road test vehicle and check if instrument cluster indicates road speed. If road speed is not indicated, repair or replace speed sensor/instrument cluster. If road speed is indicated, check wiring harness between ECM and instrument cluster. If necessary, repair wiring harness. Check for faulty ECM.

DTC 69: Park/Neutral Position Switch

1. With transmission In Park or Neutral, measure voltage at terminal No. 3 (Red/Blue wire) of PCM Yellow connector. Voltage should not be present. If 5 volts is present, reset gear selector switches and/or check decoder module. Clear codes and retest
2. If 5 volts is not present, check for continuity between ground and terminal No. 3 (Red/Blue wire) of PCM Yellow connector. With transmission in Park or Neutral, continuity should exist (terminal No. 3 grounded). If continuity exists, replace PCM. If continuity does not exist, locate and repair open in Red/Blue wire.

DTC 89: EVAP Canister Purge Control Valve

Check wiring harness and connectors for intermittent fault. Check EVAP canister purge control valve function. Valve is functional if "click" can be heard or if touch can detect it is functioning properly. Check for faulty ECM.