Code 69
DRIVE/NEUTRAL INPUT CIRCUIT - DTC 69
The ECM looks for an incorrect gear position (DRIVE; NEUTRAL) input signal. The ECM uses the gear position input for idle control functions. The controlled idle speed in DRIVE is lower than in NEUTRAL.
The ECM outputs a 5 volt gear position sensor signal on the low power (yellow) connector, pin 3. When the gear selector is in PARK or NEUTRAL, the voltage signal is switched to ground by an external device and pin 3 voltage becomes zero.
On XJ6 Sedan Range vehicles, the gear position sensor signal is switched to ground by the decoder module, which receives gear position information from the transmission rotary switch. On 1990 - 92 MY vehicles, the decoder module is located above the component panel behind the right side under dash panel.
On XJS vehicles, the gear position sensor signal is switched to ground by the transmission rotary switch.
The ECM will flag DTC 69 if the gear position is not PARK or NEUTRAL when the engine is started. DTC 69 will also flag if the gear position is PARK or NEUTRAL when the engine load and speed are high.
Condition Required For DTC 69 Flagging
Engine speed - Greater than 3550 rpm.
Engine load site - Load site 12 or higher.
Gear position voltage signal - Less than 1 volt (PARK / NEUTRAL)
Engine speed - Less than 200 rpm.
Gear position voltage signal - 5 volts (DRIVE GEAR).
Response time - 83 engine revolutions.
Limp Home Default
None
Possible Faults
- Low battery voltage.
- Ignition switched too quickly from OFF to START (XJ6 Sedan Range up to VIN 645802)
- Gear shift cable incorrectly adjusted.
- Transmission rotary switch incorrectly adjusted.
- Open circuit or short circuit wiring between the ECM and the decoder module (XJ6 Sedan Range)
- Open circuit or short circuit wiring between the ECM and the transmission rotary switch. (XJS Range)
- Defective ECM.
Diagnostic Notes
1. The gear position sensor signal can be monitored using the PDU "Datalogger" function. In PARK and NEUTRAL, the signal is 0; in all other gear positions, the signal is 1. The PDU Datalogger can be set to trigger on flagging DTC 69.
2. Test for a DTC reoccurrence by road testing the vehicle. Accelerate at full throttle to above 3550 rpm.
3. A revised decoder module was introduced on XJ6 Sedan Range vehicles at VIN 645803 to prevent false flagging of DTC 69 caused by switching of the ignition too quickly from OFF to START.
4. When checking the gear shift cable and rotary switch adjustment, check the gear shift cable adjustment first. When the manual valve selector shaft is held in the NEUTRAL position by the detent, the gear selector must be centered in the NEUTRAL gate notch. Check the rotary switch adjustment using special tool JD 161.
Circuit Diagrams
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Circuit Diagram:
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Flow Chart - DTC 69
0�� Flow Chart - DTC 69:
